add spack.util.url.git_url_parse() method and tests

Add a method to parse git URLs (but not arbitrary file paths). This method parses git URLs into scheme, username, hostname, port, and path. It will raise an error if its argument is not proper git URL. - [x] add `spack.util.url.git_url_parse` method - [x] add 31 tests for `git_url_parse`
2021-09-13 21:46:52 -07:00
2443 changed files with 18741 additions and 64060 deletions
--- a/.github/workflows/bootstrap.yml
+++ b/.github/workflows/bootstrap.yml
@@ -1,8 +1,6 @@
 name: Bootstrapping

 on:
-  # This Workflow can be triggered manually
-  workflow_dispatch:
  pull_request:
    branches:
      - develop
@@ -21,7 +19,7 @@ on:

 jobs:

-  fedora-clingo-sources:
+  fedora-sources:
    runs-on: ubuntu-latest
    container: "fedora:latest"
    steps:
@@ -31,7 +29,7 @@ jobs:
              bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
              make patch unzip which xz python3 python3-devel tree \
              cmake bison bison-devel libstdc++-static
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+      - uses: actions/checkout@v2
      - name: Setup repo and non-root user
        run: |
          git --version
@@ -48,7 +46,7 @@ jobs:
          spack -d solve zlib
          tree ~/.spack/bootstrap/store/

-  ubuntu-clingo-sources:
+  ubuntu-sources:
    runs-on: ubuntu-latest
    container: "ubuntu:latest"
    steps:
@@ -61,7 +59,7 @@ jobs:
              bzip2 curl file g++ gcc gfortran git gnupg2 gzip \
              make patch unzip xz-utils python3 python3-dev tree \
              cmake bison
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+      - uses: actions/checkout@v2
      - name: Setup repo and non-root user
        run: |
          git --version
@@ -78,47 +76,18 @@ jobs:
          spack -d solve zlib
          tree ~/.spack/bootstrap/store/

-  ubuntu-clingo-binaries-and-patchelf:
+  opensuse-sources:
    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc gfortran git gnupg2 gzip \
-              make patch unzip xz-utils python3 python3-dev tree
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-      - name: Setup repo and non-root user
-        run: |
-          git --version
-          git fetch --unshallow
-          . .github/workflows/setup_git.sh
-          useradd -m spack-test
-          chown -R spack-test .
-      - name: Bootstrap clingo
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack -d solve zlib
-          tree ~/.spack/bootstrap/store/
-
-
-  opensuse-clingo-sources:
-    runs-on: ubuntu-latest
-    container: "opensuse/leap:latest"
+    container: "opensuse/tumbleweed:latest"
    steps:
      - name: Install dependencies
        run: |
-          # Harden CI by applying the workaround described here: https://www.suse.com/support/kb/doc/?id=000019505
-          zypper update -y || zypper update -y
+          zypper update -y
          zypper install -y \
              bzip2 curl file gcc-c++ gcc gcc-fortran tar git gpg2 gzip \
              make patch unzip which xz python3 python3-devel tree \
              cmake bison
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+      - uses: actions/checkout@v2
      - name: Setup repo and non-root user
        run: |
          git --version
@@ -132,13 +101,13 @@ jobs:
          spack -d solve zlib
          tree ~/.spack/bootstrap/store/

-  macos-clingo-sources:
+  macos-sources:
    runs-on: macos-latest
    steps:
      - name: Install dependencies
        run: |
          brew install cmake bison@2.7 tree
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+      - uses: actions/checkout@v2
      - name: Bootstrap clingo
        run: |
          source share/spack/setup-env.sh
@@ -157,8 +126,8 @@ jobs:
      - name: Install dependencies
        run: |
          brew install tree
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-      - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
        with:
          python-version: ${{ matrix.python-version }}
      - name: Bootstrap clingo
@@ -168,14 +137,15 @@ jobs:
          spack -d solve zlib
          tree ~/.spack/bootstrap/store/

+
  ubuntu-clingo-binaries:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ['2.7', '3.5', '3.6', '3.7', '3.8', '3.9']
    steps:
-      - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-      - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
        with:
          python-version: ${{ matrix.python-version }}
      - name: Setup repo and non-root user
@@ -189,94 +159,3 @@ jobs:
          spack bootstrap untrust spack-install
          spack -d solve zlib
          tree ~/.spack/bootstrap/store/
-
-  ubuntu-gnupg-binaries:
-    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc patchelf gfortran git gzip \
-              make patch unzip xz-utils python3 python3-dev tree
-      - uses: actions/checkout@v2
-      - name: Setup repo and non-root user
-        run: |
-          git --version
-          git fetch --unshallow
-          . .github/workflows/setup_git.sh
-          useradd -m spack-test
-          chown -R spack-test .
-      - name: Bootstrap GnuPG
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack bootstrap untrust spack-install
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
-
-  ubuntu-gnupg-sources:
-    runs-on: ubuntu-latest
-    container: "ubuntu:latest"
-    steps:
-      - name: Install dependencies
-        env:
-          DEBIAN_FRONTEND: noninteractive
-        run: |
-          apt-get update -y && apt-get upgrade -y
-          apt-get install -y \
-              bzip2 curl file g++ gcc patchelf gfortran git gzip \
-              make patch unzip xz-utils python3 python3-dev tree \
-              gawk
-      - uses: actions/checkout@v2
-      - name: Setup repo and non-root user
-        run: |
-          git --version
-          git fetch --unshallow
-          . .github/workflows/setup_git.sh
-          useradd -m spack-test
-          chown -R spack-test .
-      - name: Bootstrap GnuPG
-        shell: runuser -u spack-test -- bash {0}
-        run: |
-          source share/spack/setup-env.sh
-          spack solve zlib
-          spack bootstrap untrust github-actions
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
-
-  macos-gnupg-binaries:
-    runs-on: macos-latest
-    steps:
-      - name: Install dependencies
-        run: |
-          brew install tree
-          # Remove GnuPG since we want to bootstrap it
-          sudo rm -rf /usr/local/bin/gpg
-      - uses: actions/checkout@v2
-      - name: Bootstrap GnuPG
-        run: |
-          source share/spack/setup-env.sh
-          spack bootstrap untrust spack-install
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
-
-  macos-gnupg-sources:
-    runs-on: macos-latest
-    steps:
-      - name: Install dependencies
-        run: |
-          brew install gawk tree
-          # Remove GnuPG since we want to bootstrap it
-          sudo rm -rf /usr/local/bin/gpg
-      - uses: actions/checkout@v2
-      - name: Bootstrap GnuPG
-        run: |
-          source share/spack/setup-env.sh
-          spack solve zlib
-          spack bootstrap untrust github-actions
-          spack -d gpg list
-          tree ~/.spack/bootstrap/store/
--- a/.github/workflows/build-containers.yml
+++ b/.github/workflows/build-containers.yml
@@ -1,27 +1,15 @@
-name: Containers
-
+name: Build & Deploy Docker Containers
 on:
-  # This Workflow can be triggered manually
-  workflow_dispatch:
  # Build new Spack develop containers nightly.
  schedule:
    - cron: '34 0 * * *'
-  # Run on pull requests that modify this file
-  pull_request:
-    branches:
-      - develop
-    paths:
-      - '.github/workflows/build-containers.yml'
-      - 'share/spack/docker/*'
  # Let's also build & tag Spack containers on releases.
  release:
    types: [published]

 jobs:
  deploy-images:
-    runs-on: ubuntu-latest
-    permissions:
-      packages: write
+    runs-on: ubuntu-latest 
    strategy:
      # Even if one container fails to build we still want the others
      # to continue their builds.
@@ -29,19 +17,19 @@ jobs:
      # A matrix of Dockerfile paths, associated tags, and which architectures
      # they support.
      matrix:
-        dockerfile: [[amazon-linux, amazonlinux-2.dockerfile, 'linux/amd64,linux/arm64'],
-                     [centos7, centos-7.dockerfile, 'linux/amd64,linux/arm64,linux/ppc64le'],
-                     [leap15, leap-15.dockerfile, 'linux/amd64,linux/arm64,linux/ppc64le'],
-                     [ubuntu-xenial, ubuntu-1604.dockerfile, 'linux/amd64,linux/arm64,linux/ppc64le'],
-                     [ubuntu-bionic, ubuntu-1804.dockerfile, 'linux/amd64,linux/arm64,linux/ppc64le']]
+        dockerfile: [[amazon-linux, amazonlinux-2.dockerfile, 'linux/amd64,linux/arm64'], 
+                     [centos7, centos-7.dockerfile, 'linux/amd64,linux/arm64'],
+                     [leap15, leap-15.dockerfile, 'linux/amd64,linux/arm64'],
+                     [ubuntu-xenial, ubuntu-1604.dockerfile, 'linux/amd64,linux/arm64'],
+                     [ubuntu-bionic, ubuntu-1804.dockerfile, 'linux/amd64,linux/arm64']]
    name: Build ${{ matrix.dockerfile[0] }}
    steps:
      - name: Checkout
-        uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+        uses: actions/checkout@v2

      - name: Set Container Tag Normal (Nightly)
        run: |
-          container="${{ matrix.dockerfile[0] }}:latest"
+          container="ghcr.io/spack/${{ matrix.dockerfile[0]}}:latest"
          echo "container=${container}" >> $GITHUB_ENV
          echo "versioned=${container}" >> $GITHUB_ENV

@@ -49,7 +37,7 @@ jobs:
      - name: Set Container Tag on Release
        if: github.event_name == 'release'
        run: |
-          versioned="${{matrix.dockerfile[0]}}:${GITHUB_REF##*/}"
+          versioned="ghcr.io/spack/${{matrix.dockerfile[0]}}:${GITHUB_REF##*/}"
          echo "versioned=${versioned}" >> $GITHUB_ENV

      - name: Check ${{ matrix.dockerfile[1] }} Exists
@@ -60,34 +48,25 @@ jobs:
              exit 1;
          fi

-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@27d0a4f181a40b142cce983c5393082c365d1480 # @v1
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@94ab11c41e45d028884a99163086648e898eed25 # @v1
-
      - name: Log in to GitHub Container Registry
-        uses: docker/login-action@42d299face0c5c43a0487c477f595ac9cf22f1a7 # @v1
+        uses: docker/login-action@v1
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

-      - name: Log in to DockerHub
-        if: ${{ github.event_name != 'pull_request' }}
-        uses: docker/login-action@42d299face0c5c43a0487c477f595ac9cf22f1a7 # @v1
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1

      - name: Build & Deploy ${{ matrix.dockerfile[1] }}
-        uses: docker/build-push-action@a66e35b9cbcf4ad0ea91ffcaf7bbad63ad9e0229 # @v2
+        uses: docker/build-push-action@v2
        with:
          file: share/spack/docker/${{matrix.dockerfile[1]}}
          platforms: ${{ matrix.dockerfile[2] }}
-          push: ${{ github.event_name != 'pull_request' }}
+          push: true
          tags: |
-            spack/${{ env.container }}
-            spack/${{ env.versioned }}
-            ghcr.io/spack/${{ env.container }}
-            ghcr.io/spack/${{ env.versioned }}
+            ${{ env.container }}
+            ${{ env.versioned }}
--- a/.github/workflows/macos_python.yml
+++ b/.github/workflows/macos_python.yml
@@ -24,8 +24,8 @@ jobs:
    name: gcc with clang
    runs-on: macos-latest
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: spack install
@@ -39,8 +39,8 @@ jobs:
    runs-on: macos-latest
    timeout-minutes: 700
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: spack install
@@ -52,8 +52,8 @@ jobs:
    name: scipy, mpl, pd
    runs-on: macos-latest
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: spack install
@@ -62,3 +62,17 @@ jobs:
        spack install -v --fail-fast py-scipy %apple-clang
        spack install -v --fail-fast py-matplotlib %apple-clang
        spack install -v --fail-fast py-pandas %apple-clang
+
+  install_mpi4py_clang:
+    name: mpi4py, petsc4py
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.9
+    - name: spack install
+      run: |
+        . .github/workflows/install_spack.sh
+        spack install -v --fail-fast py-mpi4py %apple-clang
+        spack install -v --fail-fast py-petsc4py %apple-clang
--- a/.github/workflows/setup_git.sh
+++ b/.github/workflows/setup_git.sh
@@ -1,8 +1,9 @@
-#!/bin/bash -e
+#!/usr/bin/env sh
 git config --global user.email "spack@example.com"
 git config --global user.name "Test User"
-
-# create a local pr base branch
-if [[ -n $GITHUB_BASE_REF ]]; then
-    git fetch origin "${GITHUB_BASE_REF}:${GITHUB_BASE_REF}"
+# With fetch-depth: 0 we have a remote develop
+# but not a local branch. Don't do this on develop
+if [ "$(git branch --show-current)" != "develop" ]
+then
+  git branch develop origin/develop
 fi
--- a/.github/workflows/unit_tests.yaml
+++ b/.github/workflows/unit_tests.yaml
@@ -15,8 +15,8 @@ jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: Install Python Packages
@@ -24,17 +24,17 @@ jobs:
        pip install --upgrade pip
        pip install --upgrade vermin
    - name: vermin (Spack's Core)
-      run: vermin --backport argparse --violations --backport typing -t=2.7- -t=3.5- -vvv lib/spack/spack/ lib/spack/llnl/ bin/
+      run: vermin --backport argparse --violations --backport typing -t=2.6- -t=3.5- -vvv lib/spack/spack/ lib/spack/llnl/ bin/
    - name: vermin (Repositories)
-      run: vermin --backport argparse --violations --backport typing -t=2.7- -t=3.5- -vvv var/spack/repos
+      run: vermin --backport argparse --violations --backport typing -t=2.6- -t=3.5- -vvv var/spack/repos
  # Run style checks on the files that have been changed
  style:
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
      with:
        fetch-depth: 0
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: Install Python packages
@@ -48,6 +48,26 @@ jobs:
    - name: Run style tests
      run: |
          share/spack/qa/run-style-tests
+  # Build the documentation
+  documentation:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.9
+    - name: Install System packages
+      run: |
+        sudo apt-get -y update
+        sudo apt-get install -y coreutils ninja-build graphviz
+    - name: Install Python packages
+      run: |
+        pip install --upgrade pip six setuptools
+        pip install --upgrade -r lib/spack/docs/requirements.txt
+    - name: Build documentation
+      run: |
+          share/spack/qa/run-doc-tests
+
  # Check which files have been updated by the PR
  changes:
    runs-on: ubuntu-latest
@@ -57,12 +77,12 @@ jobs:
      packages: ${{ steps.filter.outputs.packages }}
      with_coverage: ${{ steps.coverage.outputs.with_coverage }}
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
      if: ${{ github.event_name == 'push' }}
      with:
        fetch-depth: 0
    # For pull requests it's not necessary to checkout the code
-    - uses: dorny/paths-filter@b2feaf19c27470162a626bd6fa8438ae5b263721
+    - uses: dorny/paths-filter@v2
      id: filter
      with:
        # See https://github.com/dorny/paths-filter/issues/56 for the syntax used below
@@ -92,24 +112,17 @@ jobs:

  # Run unit tests with different configurations on linux
  unittests:
-    needs: [ validate, style, changes ]
+    needs: [ validate, style, documentation, changes ]
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9]
-        concretizer: ['clingo']
-        include:
-        - python-version: 2.7
-          concretizer: original
-        - python-version: 3.6
-          concretizer: original
-        - python-version: 3.9
-          concretizer: original
+        concretizer: ['original', 'clingo']
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
      with:
        fetch-depth: 0
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/setup-python@v2
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install System packages
@@ -121,7 +134,7 @@ jobs:
              patchelf cmake bison libbison-dev kcov
    - name: Install Python packages
      run: |
-          pip install --upgrade pip six setuptools pytest codecov coverage[toml]
+          pip install --upgrade pip six setuptools codecov coverage[toml]
          # ensure style checks are not skipped in unit tests for python >= 3.6
          # note that true/false (i.e., 1/0) are opposite in conditions in python and bash
          if python -c 'import sys; sys.exit(not sys.version_info >= (3, 6))'; then
@@ -158,19 +171,19 @@ jobs:
          SPACK_TEST_SOLVER: ${{ matrix.concretizer }}
      run: |
          share/spack/qa/run-unit-tests
-    - uses: codecov/codecov-action@f32b3a3741e1053eb607407145bc9619351dc93b # @v2.1.0
+    - uses: codecov/codecov-action@v2.0.3
      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
      with:
        flags: unittests,linux,${{ matrix.concretizer }}
  # Test shell integration
  shell:
-    needs: [ validate, style, changes ]
+    needs: [ validate, style, documentation, changes ]
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
      with:
        fetch-depth: 0
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: Install System packages
@@ -180,7 +193,7 @@ jobs:
          sudo apt-get install -y coreutils kcov csh zsh tcsh fish dash bash
    - name: Install Python packages
      run: |
-          pip install --upgrade pip six setuptools pytest codecov coverage[toml]
+          pip install --upgrade pip six setuptools codecov coverage[toml]
    - name: Setup git configuration
      run: |
          # Need this for the git tests to succeed.
@@ -196,15 +209,44 @@ jobs:
          COVERAGE: true
      run: |
          share/spack/qa/run-shell-tests
-    - uses: codecov/codecov-action@f32b3a3741e1053eb607407145bc9619351dc93b # @v2.1.0
+    - uses: codecov/codecov-action@v2.0.3
      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
      with:
        flags: shelltests,linux
+  # Test for Python2.6 run on Centos 6
+  centos6:
+    needs: [ validate, style, documentation, changes ]
+    runs-on: ubuntu-latest
+    container: spack/github-actions:centos6
+    steps:
+    - name: Run unit tests (full test-suite)
+      # The CentOS 6 container doesn't run with coverage, but
+      # under the same conditions it runs the full test suite
+      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
+      env:
+          HOME: /home/spack-test
+      run: |
+          whoami && echo $HOME && cd $HOME
+          git clone https://github.com/spack/spack.git && cd spack
+          git fetch origin ${{ github.ref }}:test-branch
+          git checkout test-branch
+          share/spack/qa/run-unit-tests
+    - name: Run unit tests (only package tests)
+      if: ${{ needs.changes.outputs.with_coverage == 'false' }}
+      env:
+          HOME: /home/spack-test
+          ONLY_PACKAGES: true
+      run: |
+          whoami && echo $HOME && cd $HOME
+          git clone https://github.com/spack/spack.git && cd spack
+          git fetch origin ${{ github.ref }}:test-branch
+          git checkout test-branch
+          share/spack/qa/run-unit-tests

  # Test RHEL8 UBI with platform Python. This job is run
  # only on PRs modifying core Spack
  rhel8-platform-python:
-    needs: [ validate, style, changes ]
+    needs: [ validate, style, documentation, changes ]
    runs-on: ubuntu-latest
    if: ${{ needs.changes.outputs.with_coverage == 'true' }}
    container: registry.access.redhat.com/ubi8/ubi
@@ -214,7 +256,7 @@ jobs:
          dnf install -y \
              bzip2 curl file gcc-c++ gcc gcc-gfortran git gnupg2 gzip \
              make patch tcl unzip which xz
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
    - name: Setup repo and non-root user
      run: |
          git --version
@@ -226,17 +268,16 @@ jobs:
      shell: runuser -u spack-test -- bash {0}
      run: |
          source share/spack/setup-env.sh
-          spack -d solve zlib
          spack unit-test -k 'not cvs and not svn and not hg' -x --verbose
  # Test for the clingo based solver (using clingo-cffi)
  clingo-cffi:
-    needs: [ validate, style, changes ]
+    needs: [ validate, style, documentation, changes ]
    runs-on: ubuntu-latest
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
      with:
        fetch-depth: 0
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/setup-python@v2
      with:
        python-version: 3.9
    - name: Install System packages
@@ -248,7 +289,7 @@ jobs:
              patchelf kcov
    - name: Install Python packages
      run: |
-          pip install --upgrade pip six setuptools pytest codecov coverage[toml] clingo
+          pip install --upgrade pip six setuptools codecov coverage[toml] clingo
    - name: Setup git configuration
      run: |
          # Need this for the git tests to succeed.
@@ -270,28 +311,28 @@ jobs:
          SPACK_TEST_SOLVER: clingo
      run: |
          share/spack/qa/run-unit-tests
-    - uses: codecov/codecov-action@f32b3a3741e1053eb607407145bc9619351dc93b # @v2.1.0
+    - uses: codecov/codecov-action@v2.0.3
      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
      with:
        flags: unittests,linux,clingo
  # Run unit tests on MacOS
  build:
-    needs: [ validate, style, changes ]
+    needs: [ validate, style, documentation, changes ]
    runs-on: macos-latest
    strategy:
      matrix:
        python-version: [3.8]
    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
+    - uses: actions/checkout@v2
      with:
        fetch-depth: 0
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
+    - uses: actions/setup-python@v2
      with:
        python-version: ${{ matrix.python-version }}
    - name: Install Python packages
      run: |
          pip install --upgrade pip six setuptools
-          pip install --upgrade pytest codecov coverage[toml]
+          pip install --upgrade codecov coverage[toml]
    - name: Setup Homebrew packages
      run: |
        brew install dash fish gcc gnupg2 kcov
@@ -316,37 +357,8 @@ jobs:
          echo "ONLY PACKAGE RECIPES CHANGED [skipping coverage]"
          $(which spack) unit-test -x -m "not maybeslow" -k "package_sanity"
        fi
-    - uses: codecov/codecov-action@f32b3a3741e1053eb607407145bc9619351dc93b # @v2.1.0
+    - uses: codecov/codecov-action@v2.0.3
      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
      with:
        files: ./coverage.xml
        flags: unittests,macos
-
-  # Run audits on all the packages in the built-in repository
-  package-audits:
-    needs: [ validate, style, changes ]
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579 # @v2
-    - uses: actions/setup-python@dc73133d4da04e56a135ae2246682783cc7c7cb6 # @v2
-      with:
-        python-version: 3.9
-    - name: Install Python packages
-      run: |
-        pip install --upgrade pip six setuptools pytest codecov coverage[toml]
-    - name: Package audits (with coverage)
-      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
-      run: |
-          . share/spack/setup-env.sh
-          coverage run $(which spack) audit packages
-          coverage combine
-          coverage xml
-    - name: Package audits (wwithout coverage)
-      if: ${{ needs.changes.outputs.with_coverage == 'false' }}
-      run: |
-          . share/spack/setup-env.sh
-          $(which spack) audit packages
-    - uses: codecov/codecov-action@f32b3a3741e1053eb607407145bc9619351dc93b # @v2.1.0
-      if: ${{ needs.changes.outputs.with_coverage == 'true' }}
-      with:
-        flags: unittests,linux,audits
--- a/.gitignore
+++ b/.gitignore
@@ -132,11 +132,11 @@ celerybeat.pid
 .env
 .venv
 env/
+!/lib/spack/env
 venv/
 ENV/
 env.bak/
 venv.bak/
-!/lib/spack/env

 # Spyder project settings
 .spyderproject
@@ -210,9 +210,6 @@ tramp
 /eshell/history
 /eshell/lastdir

-# zsh byte-compiled files
-*.zwc
-
 # elpa packages
 /elpa/

--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -2,7 +2,6 @@ version: 2

 sphinx:
  configuration: lib/spack/docs/conf.py
-  fail_on_warning: true

 python:
  version: 3.7
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,212 +1,3 @@
-# v0.17.1 (2021-12-23)
-
-### Spack Bugfixes
-* Allow locks to work under high contention (#27846)
-* Improve errors messages from clingo (#27707 #27970)
-* Respect package permissions for sbang (#25764)
-* Fix --enable-locks behavior (#24675)
-* Fix log-format reporter ignoring install errors (#25961)
-* Fix overloaded argparse keys (#27379)
-* Allow style commands to run with targets other than "develop" (#27472)
-* Log lock messages to debug level, instead of verbose level (#27408)
-* Handle invalid unicode while logging (#21447)
-* spack audit: fix API calls to variants (#27713)
-* Provide meaningful message for empty environment installs (#28031)
-* Added opensuse leap containers to spack containerize (#27837)
-* Revert "patches: make re-applied patches idempotent" (#27625)
-* MANPATH can use system defaults (#21682)
-* Add "setdefault" subcommand to `spack module tcl` (#14686)
-* Regenerate views when specs already installed (#28113)
-
-### Package bugfixes
-* Fix external package detection for OpenMPI (#27255)
-* Update the UPC++ package to 2021.9.0 (#26996)
-* Added py-vermin v1.3.2 (#28072)
-
-# v0.17.0 (2021-11-05)
-
-`v0.17.0` is a major feature release.
-
-## Major features in this release
-
-1. **New concretizer is now default**
-   The new concretizer introduced as an experimental feature in `v0.16.0`
-   is now the default (#25502). The new concretizer is based on the
-   [clingo](https://github.com/potassco/clingo) logic programming system,
-   and it enables us to do much higher quality and faster dependency solving
-   The old concretizer is still available via the `concretizer: original`
-   setting, but it is deprecated and will be removed in `v0.18.0`.
-
-2. **Binary Bootstrapping**
-   To make it easier to use the new concretizer and binary packages,
-   Spack now bootstraps `clingo` and `GnuPG` from public binaries. If it
-   is not able to bootstrap them from binaries, it installs them from
-   source code. With these changes, you should still be able to clone Spack
-   and start using it almost immediately. (#21446, #22354, #22489, #22606,
-   #22720, #22720, #23677, #23946, #24003, #25138, #25607, #25964, #26029,
-   #26399, #26599).
-
-3. **Reuse existing packages (experimental)**
-   The most wanted feature from our
-   [2020 user survey](https://spack.io/spack-user-survey-2020/) and
-   the most wanted Spack feature of all time (#25310). `spack install`,
-   `spack spec`, and `spack concretize` now have a `--reuse` option, which
-   causes Spack to minimize the number of rebuilds it does. The `--reuse`
-   option will try to find existing installations and binary packages locally
-   and in registered mirrors, and will prefer to use them over building new
-   versions. This will allow users to build from source *far* less than in
-   prior versions of Spack. This feature will continue to be improved, with
-   configuration options and better CLI expected in `v0.17.1`. It will become
-   the *default* concretization mode in `v0.18.0`.
-
-4. **Better error messages**
-   We have improved the error messages generated by the new concretizer by
-   using *unsatisfiable cores*. Spack will now print a summary of the types
-   of constraints that were violated to make a spec unsatisfiable (#26719).
-
-5. **Conditional variants**
-   Variants can now have a `when="<spec>"` clause, allowing them to be
-   conditional based on the version or other attributes of a package (#24858).
-
-6. **Git commit versions**
-   In an environment and on the command-line, you can now provide a full,
-   40-character git commit as a version for any package with a top-level
-   `git` URL.  e.g., `spack install hdf5@45bb27f58240a8da7ebb4efc821a1a964d7712a8`.
-   Spack will compare the commit to tags in the git repository to understand
-   what versions it is ahead of or behind.
-
-7. **Override local config and cache directories**
-   You can now set `SPACK_DISABLE_LOCAL_CONFIG` to disable the `~/.spack` and
-   `/etc/spack` configuration scopes. `SPACK_USER_CACHE_PATH` allows you to
-   move caches out of `~/.spack`, as well (#27022, #26735). This addresses
-   common problems where users could not isolate CI environments from local
-   configuration.
-
-8. **Improvements to Spack Containerize**
-   For added reproducibility, you can now pin the Spack version used by
-   `spack containerize` (#21910). The container build will only build
-   with the Spack version pinned at build recipe creation instead of the
-   latest Spack version.
-
-9. **New commands for dealing with tags**
-   The `spack tags` command allows you to list tags on packages (#26136), and you
-   can list tests and filter tags with `spack test list` (#26842).
-
-## Other new features of note
-
-* Copy and relocate environment views as stand-alone installations (#24832)
-* `spack diff` command can diff two installed specs (#22283, #25169)
-* `spack -c <config>` can set one-off config parameters on CLI (#22251)
-* `spack load --list` is an alias for `spack find --loaded` (#27184)
-* `spack gpg` can export private key with `--secret` (#22557)
-* `spack style` automatically bootstraps dependencies (#24819)
-* `spack style --fix` automatically invokes `isort` (#24071)
-* build dependencies can be installed from build caches with `--include-build-deps` (#19955)
-* `spack audit` command for checking package constraints (#23053)
-* Spack can now fetch from `CVS` repositories (yep, really) (#23212)
-* `spack monitor` lets you upload analysis about installations to a
-  [spack monitor server](https://github.com/spack/spack-monitor) (#23804, #24321,
-  #23777, #25928))
-* `spack python --path` shows which `python` Spack is using (#22006)
-* `spack env activate --temp` can create temporary environments (#25388)
-* `--preferred` and `--latest` options for `spack checksum` (#25830)
-* `cc` is now pure posix and runs on Alpine (#26259)
-* `SPACK_PYTHON` environment variable sets which `python` spack uses (#21222)
-* `SPACK_SKIP_MODULES` lets you source `setup-env.sh` faster if you don't need modules (#24545)
-
-## Major internal refactors
-
-* `spec.yaml` files are now `spec.json`, yielding a large speed improvement (#22845)
-* Splicing allows Spack specs to store mixed build provenance (#20262)
-* More extensive hooks API for installations (#21930)
-* New internal API for getting the active environment (#25439)
-
-## Performance Improvements
-
-* Parallelize separate concretization in environments; Previously 55 min E4S solve
-    now takes 2.5 min (#26264)
-* Drastically improve YamlFilesystemView file removal performance via batching (#24355)
-* Speed up spec comparison (#21618)
-* Speed up environment activation (#25633)
-
-## Archspec improvements
-* support for new generic `x86_64_v2`, `x86_64_v3`, `x86_64_v4` targets
-    (see [archspec#31](https://github.com/archspec/archspec-json/pull/31))
-* `spack arch --generic` lets you get the best generic architecture for
-    your node (#27061)
-* added support for aocc (#20124), `arm` compiler on `graviton2` (#24904)
-    and on `a64fx` (#24524),
-
-## Infrastructure, buildcaches, and services
-
-* Add support for GCS Bucket Mirrors (#26382)
-* Add `spackbot` to help package maintainers with notifications. See
-  [spack.github.io/spackbot](https://spack.github.io/spackbot/)
-* Reproducible pipeline builds with `spack ci rebuild` (#22887)
-* Removed redundant concretizations from GitLab pipeline generation (#26622)
-* Spack CI no longer generates jobs for unbuilt specs (#20435)
-* Every pull request pipeline has its own buildcache (#25529)
-* `--no-add` installs only specified specs and only if already present in… (#22657)
-* Add environment-aware `spack buildcache sync` command (#25470)
-* Binary cache installation speedups and improvements (#19690, #20768)
-
-## Deprecations and Removals
-
-* `spack setup` was deprecated in v0.16.0, and has now been removed.
-  Use `spack develop` and `spack dev-build`.
-* Remove unused `--dependencies` flag from `spack load` (#25731)
-* Remove stubs for `spack module [refresh|find|rm|loads]`, all of which
-  were deprecated in 2018.
-
-## Notable Bugfixes
-
-* Deactivate previous env before activating new one (#25409)
-* Many fixes to error codes from `spack install` (#21319, #27012, #25314)
-* config add: infer type based on JSON schema validation errors (#27035)
-* `spack config edit` now works even if `spack.yaml` is broken (#24689)
-
-## Packages
-
-* Allow non-empty version ranges like `1.1.0:1.1` (#26402)
-* Remove `.99`'s from many version ranges (#26422)
-* Python: use platform-specific site packages dir (#25998)
-* `CachedCMakePackage` for using *.cmake initial config files (#19316)
-* `lua-lang` allows swapping `lua` and `luajit` (#22492)
-* Better support for `ld.gold` and `ld.lld` (#25626)
-* build times are now stored as metadata in `$prefix/.spack` (#21179)
-* post-install tests can be reused in smoke tests (#20298)
-* Packages can use `pypi` attribute to infer `homepage`/`url`/`list_url` (#17587)
-* Use gnuconfig package for `config.guess` file replacement (#26035)
-* patches: make re-applied patches idempotent (#26784)
-
-## Spack community stats
-
-* 5969 total packages, 920 new since `v0.16.0`
-    * 358 new Python packages, 175 new R packages
-* 513 people contributed to this release
-    * 490 committers to packages
-    * 105 committers to core
-* Lots of GPU updates:
-    * ~77 CUDA-related commits
-    * ~66 AMD-related updates
-    * ~27 OneAPI-related commits
-    * 30 commits from AMD toolchain support
-* `spack test` usage in packages is increasing
-    * 1669 packages with tests (mostly generic python tests)
-    * 93 packages with their own tests
-
-
-# v0.16.3 (2021-09-21)
-
-* clang/llvm: fix version detection (#19978)
-* Fix use of quotes in Python build system (#22279)
-* Cray: fix extracting paths from module files (#23472)
-* Use AWS CloudFront for source mirror (#23978)
-* Ensure all roots of an installed environment are marked explicit in db (#24277)
-* Fix fetching for Python 3.8 and 3.9 (#24686)
-* locks: only open lockfiles once instead of for every lock held (#24794)
-* Remove the EOL centos:6 docker image
-
 # v0.16.2 (2021-05-22)

 * Major performance improvement for `spack load` and other commands. (#23661)
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -1,58 +0,0 @@
-# If you are referencing Spack in a publication, please cite the SC'15 paper
-# described here.
-#
-# Here's the raw citation:
-#
-#   Todd Gamblin, Matthew P. LeGendre, Michael R. Collette, Gregory L. Lee,
-#   Adam Moody, Bronis R. de Supinski, and W. Scott Futral.
-#   The Spack Package Manager: Bringing Order to HPC Software Chaos.
-#   In Supercomputing 2015 (SC’15), Austin, Texas, November 15-20 2015. LLNL-CONF-669890.
-#
-# Or, in BibTeX:
-#
-# @inproceedings{Gamblin_The_Spack_Package_2015,
-#     address = {Austin, Texas, USA},
-#     author = {Gamblin, Todd and LeGendre, Matthew and
-#               Collette, Michael R. and Lee, Gregory L. and
-#               Moody, Adam and de Supinski, Bronis R. and Futral, Scott},
-#     doi = {10.1145/2807591.2807623},
-#     month = {November 15-20},
-#     note = {LLNL-CONF-669890},
-#     series = {Supercomputing 2015 (SC’15)},
-#     title = {{The Spack Package Manager: Bringing Order to HPC Software Chaos}},
-#     url = {https://github.com/spack/spack},
-#     year = {2015}
-# }
-#
-# And here's the CITATION.cff format:
-#
-cff-version: 1.2.0
-message: "If you are referencing Spack in a publication, please cite the paper below."
-preferred-citation:
-  type: conference-paper
-  doi: "10.1145/2807591.2807623"
-  url: "https://github.com/spack/spack"
-  authors:
-  - family-names: "Gamblin"
-    given-names: "Todd"
-  - family-names: "LeGendre"
-    given-names: "Matthew"
-  - family-names: "Collette"
-    given-names: "Michael R."
-  - family-names: "Lee"
-    given-names: "Gregory L."
-  - family-names: "Moody"
-    given-names: "Adam"
-  - family-names: "de Supinski"
-    given-names: "Bronis R."
-  - family-names: "Futral"
-    given-names: "Scott"
-  title: "The Spack Package Manager: Bringing Order to HPC Software Chaos"
-  conference:
-    name: "Supercomputing 2015 (SC’15)"
-    city: "Austin"
-    region: "Texas"
-    country: "USA"
-  month: November 15-20
-  year: 2015
-  notes: LLNL-CONF-669890
--- a/12
+++ b/12
@@ -38,10 +38,6 @@ PackageName: argparse
 PackageHomePage: https://pypi.python.org/pypi/argparse
 PackageLicenseDeclared: Python-2.0

-PackageName: attrs
-PackageHomePage: https://github.com/python-attrs/attrs
-PackageLicenseDeclared: MIT
-
 PackageName: ctest_log_parser
 PackageHomePage: https://github.com/Kitware/CMake
 PackageLicenseDeclared: BSD-3-Clause
@@ -50,8 +46,8 @@ PackageName: distro
 PackageHomePage: https://pypi.python.org/pypi/distro
 PackageLicenseDeclared: Apache-2.0

-PackageName: functools32
-PackageHomePage: https://github.com/MiCHiLU/python-functools32
+PackageName: functools
+PackageHomePage: https://github.com/python/cpython/blob/2.7/Lib/functools.py
 PackageLicenseDeclared: Python-2.0

 PackageName: jinja2
@@ -74,10 +70,6 @@ PackageName: py
 PackageHomePage: https://pypi.python.org/pypi/py
 PackageLicenseDeclared: MIT

-PackageName: pyrsistent
-PackageHomePage: http://github.com/tobgu/pyrsistent
-PackageLicenseDeclared: MIT
-
 PackageName: pytest
 PackageHomePage: https://pypi.python.org/pypi/pytest
 PackageLicenseDeclared: MIT
--- a/README.md
+++ b/README.md
@@ -4,7 +4,6 @@
 [![Bootstrapping](https://github.com/spack/spack/actions/workflows/bootstrap.yml/badge.svg)](https://github.com/spack/spack/actions/workflows/bootstrap.yml)
 [![macOS Builds (nightly)](https://github.com/spack/spack/workflows/macOS%20builds%20nightly/badge.svg?branch=develop)](https://github.com/spack/spack/actions?query=workflow%3A%22macOS+builds+nightly%22)
 [![codecov](https://codecov.io/gh/spack/spack/branch/develop/graph/badge.svg)](https://codecov.io/gh/spack/spack)
-[![Containers](https://github.com/spack/spack/actions/workflows/build-containers.yml/badge.svg)](https://github.com/spack/spack/actions/workflows/build-containers.yml)
 [![Read the Docs](https://readthedocs.org/projects/spack/badge/?version=latest)](https://spack.readthedocs.io)
 [![Slack](https://slack.spack.io/badge.svg)](https://slack.spack.io)

@@ -27,7 +26,7 @@ for examples and highlights.
 To install spack and your first package, make sure you have Python.
 Then:

-    $ git clone -c feature.manyFiles=true https://github.com/spack/spack.git
+    $ git clone https://github.com/spack/spack.git
    $ cd spack/bin
    $ ./spack install zlib

@@ -125,9 +124,6 @@ If you are referencing Spack in a publication, please cite the following paper:
   [**The Spack Package Manager: Bringing Order to HPC Software Chaos**](https://www.computer.org/csdl/proceedings/sc/2015/3723/00/2807623.pdf).
   In *Supercomputing 2015 (SC’15)*, Austin, Texas, November 15-20 2015. LLNL-CONF-669890.

-On GitHub, you can copy this citation in APA or BibTeX format via the "Cite this repository"
-button. Or, see the comments in `CITATION.cff` for the raw BibTeX.
-
 License
 ----------------

--- a/SECURITY.md
+++ b/SECURITY.md
@@ -1,24 +0,0 @@
-# Security Policy
-
-## Supported Versions
-
-We provide security updates for the following releases.
-For more on Spack's release structure, see
-[`README.md`](https://github.com/spack/spack#releases).
-
-
-| Version | Supported          |
-| ------- | ------------------ |
-| develop | :white_check_mark: |
-| 0.16.x  | :white_check_mark: |
-
-## Reporting a Vulnerability
-
-To report a vulnerability or other security
-issue, email maintainers@spack.io.
-
-You can expect to hear back within two days.
-If your security issue is accepted, we will do
-our best to release a fix within a week. If
-fixing the issue will take longer than this,
-we will discuss timeline options with you.
--- a/bin/spack
+++ b/bin/spack
@@ -33,11 +33,11 @@ import sys

 min_python3 = (3, 5)

-if sys.version_info[:2] < (2, 7) or (
+if sys.version_info[:2] < (2, 6) or (
    sys.version_info[:2] >= (3, 0) and sys.version_info[:2] < min_python3
 ):
    v_info = sys.version_info[:3]
-    msg = "Spack requires Python 2.7 or %d.%d or higher " % min_python3
+    msg = "Spack requires Python 2.6, 2.7 or %d.%d or higher " % min_python3
    msg += "You are running spack with Python %d.%d.%d." % v_info
    sys.exit(msg)

@@ -54,6 +54,8 @@ spack_external_libs = os.path.join(spack_lib_path, "external")

 if sys.version_info[:2] <= (2, 7):
    sys.path.insert(0, os.path.join(spack_external_libs, "py2"))
+if sys.version_info[:2] == (2, 6):
+    sys.path.insert(0, os.path.join(spack_external_libs, "py26"))

 sys.path.insert(0, spack_external_libs)

--- a/etc/spack/defaults/bootstrap.yaml
+++ b/etc/spack/defaults/bootstrap.yaml
@@ -4,7 +4,7 @@ bootstrap:
  enable: true
  # Root directory for bootstrapping work. The software bootstrapped
  # by Spack is installed in a "store" subfolder of this root directory
-  root: $user_cache_path/bootstrap
+  root: ~/.spack/bootstrap
  # Methods that can be used to bootstrap software. Each method may or
  # may not be able to bootstrap all of the software that Spack needs,
  # depending on its type.
@@ -29,4 +29,4 @@ bootstrap:
    # By default we trust bootstrapping from sources and from binaries
    # produced on Github via the workflow
    github-actions: true
-    spack-install: true
+    spack-install: true
--- a/etc/spack/defaults/config.yaml
+++ b/etc/spack/defaults/config.yaml
@@ -42,8 +42,8 @@ config:
  # (i.e., ``$TMP` or ``$TMPDIR``).
  #
  # Another option that prevents conflicts and potential permission issues is
-  # to specify `$user_cache_path/stage`, which ensures each user builds in their
-  # home directory.
+  # to specify `~/.spack/stage`, which ensures each user builds in their home
+  # directory.
  #
  # A more traditional path uses the value of `$spack/var/spack/stage`, which
  # builds directly inside Spack's instance without staging them in a
@@ -60,13 +60,13 @@ config:
  # identifies Spack staging to avoid accidentally wiping out non-Spack work.
  build_stage:
    - $tempdir/$user/spack-stage
-    - $user_cache_path/stage
+    - ~/.spack/stage
  # - $spack/var/spack/stage

  # Directory in which to run tests and store test results.
  # Tests will be stored in directories named by date/time and package
  # name/hash.
-  test_stage: $user_cache_path/test
+  test_stage: ~/.spack/test

  # Cache directory for already downloaded source tarballs and archived
  # repositories. This can be purged with `spack clean --downloads`.
@@ -75,7 +75,7 @@ config:

  # Cache directory for miscellaneous files, like the package index.
  # This can be purged with `spack clean --misc-cache`
-  misc_cache: $user_cache_path/cache
+  misc_cache: ~/.spack/cache


  # Timeout in seconds used for downloading sources etc. This only applies
@@ -134,7 +134,7 @@ config:
  # enabling locks.
  locks: true

-  # The default url fetch method to use.
+  # The default url fetch method to use. 
  # If set to 'curl', Spack will require curl on the user's system
  # If set to 'urllib', Spack will use python built-in libs to fetch
  url_fetch_method: urllib
@@ -160,10 +160,11 @@ config:
  #       sufficiently for many specs.
  #
  #   'clingo': Uses a logic solver under the hood to solve DAGs with full
-  #       backtracking and optimization for user preferences. Spack will
-  #       try to bootstrap the logic solver, if not already available.
+  #       backtracking and optimization for user preferences.
  #
-  concretizer: clingo
+  # 'clingo' currently requires the clingo ASP solver to be installed and
+  # built with python bindings. 'original' is built in.
+  concretizer: original


  # How long to wait to lock the Spack installation database. This lock is used
@@ -190,8 +191,3 @@ config:
  # Set to 'false' to allow installation on filesystems that doesn't allow setgid bit
  # manipulation by unprivileged user (e.g. AFS)
  allow_sgid: true
-
-  # Whether to set the terminal title to display status information during
-  # building and installing packages. This gives information about Spack's
-  # current progress as well as the current and total number of packages.
-  terminal_title: false
--- a/lib/spack/docs/analyze.rst
+++ b/lib/spack/docs/analyze.rst
@@ -59,7 +59,7 @@ are available:
    install_files            : install file listing read from install_manifest.json
    environment_variables    : environment variables parsed from spack-build-env.txt
    config_args              : config args loaded from spack-configure-args.txt
-    libabigail               : Application Binary Interface (ABI) features for objects
+    abigail                  : Application Binary Interface (ABI) features for objects


 In the above, the first three are fairly simple - parsing metadata files from
--- a/lib/spack/docs/basic_usage.rst
+++ b/lib/spack/docs/basic_usage.rst
@@ -31,13 +31,13 @@ colorized output with a flag

 .. code-block:: console

-    $ spack --color always find | less -R
+    $ spack --color always | less -R

 or an environment variable

 .. code-block:: console

-   $ SPACK_COLOR=always spack find | less -R
+   $ SPACK_COLOR=always spack | less -R

 --------------------------
 Listing available packages
@@ -188,34 +188,6 @@ configuration a **spec**.  In the commands above, ``mpileaks`` and
 ``mpileaks@3.0.4`` are both valid *specs*.  We'll talk more about how
 you can use them to customize an installation in :ref:`sec-specs`.

-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Reusing installed dependencies
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-.. warning::
-
-   The ``--reuse`` option described here is experimental, and it will
-   likely be replaced with a different option and configuration settings
-   in the next Spack release.
-
-By default, when you run ``spack install``, Spack tries to build a new
-version of the package you asked for, along with updated versions of
-its dependencies.  This gets you the latest versions and configurations,
-but it can result in unwanted rebuilds if you update Spack frequently.
-
-If you want Spack to try hard to reuse existing installations as dependencies,
-you can add the ``--reuse`` option:
-
-.. code-block:: console
-
-   $ spack install --reuse mpich
-
-This will not do anything if ``mpich`` is already installed.  If ``mpich``
-is not installed, but dependencies like ``hwloc`` and ``libfabric`` are,
-the ``mpich`` will be build with the installed versions, if possible.
-You can use the :ref:`spack spec -I <cmd-spack-spec>` command to see what
-will be reused and what will be built before you install.
-
 .. _cmd-spack-uninstall:

 ^^^^^^^^^^^^^^^^^^^
@@ -896,9 +868,8 @@ your path:
 These commands will add appropriate directories to your ``PATH``,
 ``MANPATH``, ``CPATH``, and ``LD_LIBRARY_PATH`` according to the
 :ref:`prefix inspections <customize-env-modifications>` defined in your
-modules configuration.
-When you no longer want to use a package, you can type unload or
-unuse similarly:
+modules configuration.  When you no longer want to use a package, you
+can type unload or unuse similarly:

 .. code-block:: console

@@ -939,22 +910,6 @@ first ``libelf`` above, you would run:

   $ spack load /qmm4kso

-To see which packages that you have loaded to your enviornment you would
-use ``spack find --loaded``.
-
-.. code-block:: console
-
-    $ spack find --loaded
-    ==> 2 installed packages
-    -- linux-debian7 / gcc@4.4.7 ------------------------------------
-    libelf@0.8.13
-
-    -- linux-debian7 / intel@15.0.0 ---------------------------------
-    libelf@0.8.13
-
-You can also use ``spack load --list`` to get the same output, but it
-does not have the full set of query options that ``spack find`` offers.
-
 We'll learn more about Spack's spec syntax in the next section.


@@ -1694,7 +1649,6 @@ and it will be added to the ``PYTHONPATH`` in your current shell:

 Now ``import numpy`` will succeed for as long as you keep your current
 session open.
-The loaded packages can be checked using ``spack find --loaded``

 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Loading Extensions via Modules
--- a/lib/spack/docs/build_systems/autotoolspackage.rst
+++ b/lib/spack/docs/build_systems/autotoolspackage.rst
@@ -112,44 +112,20 @@ phase runs:

 .. code-block:: console

-   $ autoreconf --install --verbose --force -I <aclocal-prefix>/share/aclocal
-
-In case you need to add more arguments, override ``autoreconf_extra_args``
-in your ``package.py`` on class scope like this:
-
-.. code-block:: python
-
-   autoreconf_extra_args = ["-Im4"]
+   $ libtoolize
+   $ aclocal
+   $ autoreconf --install --verbose --force

 All you need to do is add a few Autotools dependencies to the package.
 Most stable releases will come with a ``configure`` script, but if you
-check out a commit from the ``master`` branch, you would want to add:
+check out a commit from the ``develop`` branch, you would want to add:

 .. code-block:: python

-   depends_on('autoconf', type='build', when='@master')
-   depends_on('automake', type='build', when='@master')
-   depends_on('libtool',  type='build', when='@master')
-
-It is typically redundant to list the ``m4`` macro processor package as a
-dependency, since ``autoconf`` already depends on it.
-
-"""""""""""""""""""""""""""""""
-Using a custom autoreconf phase
-"""""""""""""""""""""""""""""""
-
-In some cases, it might be needed to replace the default implementation
-of the autoreconf phase with one running a script interpreter. In this
-example, the ``bash`` shell is used to run the ``autogen.sh`` script.
-
-.. code-block:: python
-
-   def autoreconf(self, spec, prefix):
-       which('bash')('autogen.sh')
-
-"""""""""""""""""""""""""""""""""""""""
-patching configure or Makefile.in files
-"""""""""""""""""""""""""""""""""""""""
+   depends_on('autoconf', type='build', when='@develop')
+   depends_on('automake', type='build', when='@develop')
+   depends_on('libtool',  type='build', when='@develop')
+   depends_on('m4',       type='build', when='@develop')

 In some cases, developers might need to distribute a patch that modifies
 one of the files used to generate ``configure`` or ``Makefile.in``.
@@ -159,57 +135,6 @@ create a new patch that directly modifies ``configure``. That way,
 Spack can use the secondary patch and additional build system
 dependencies aren't necessary.

-""""""""""""""""""""""""""""
-Old Autotools helper scripts
-""""""""""""""""""""""""""""
-
-Autotools based tarballs come with helper scripts such as ``config.sub`` and
-``config.guess``. It is the responsibility of the developers to keep these files
-up to date so that they run on every platform, but for very old software
-releases this is impossible. In these cases Spack can help to replace these
-files with newer ones, without having to add the heavy dependency on
-``automake``.
-
-Automatic helper script replacement is currently enabled by default on
-``ppc64le`` and ``aarch64``, as these are the known cases where old scripts fail.
-On these targets, ``AutotoolsPackage`` adds a build dependency on ``gnuconfig``,
-which is a very light-weight package with newer versions of the helper files.
-Spack then tries to run all the helper scripts it can find in the release, and
-replaces them on failure with the helper scripts from ``gnuconfig``.
-
-To opt out of this feature, use the following setting:
-
-.. code-block:: python
-
-   patch_config_files = False
-
-To enable it conditionally on different architectures, define a property and
-make the package depend on ``gnuconfig`` as a build dependency:
-
-.. code-block
-
-   depends_on('gnuconfig', when='@1.0:')
-
-   @property
-   def patch_config_files(self):
-      return self.spec.satisfies("@1.0:")
-
-.. note::
-
-    On some exotic architectures it is necessary to use system provided
-    ``config.sub`` and ``config.guess`` files. In this case, the most
-    transparent solution is to mark the ``gnuconfig`` package as external and
-    non-buildable, with a prefix set to the directory containing the files:
-
-   .. code-block:: yaml
-
-       gnuconfig:
-         buildable: false
-         externals:
-         - spec: gnuconfig@master
-           prefix: /usr/share/configure_files/
-
-
 """"""""""""""""
 force_autoreconf
 """"""""""""""""
@@ -399,47 +324,8 @@ options:

   --with-libfabric=</path/to/libfabric>

-"""""""""""""""""""""""
-The ``variant`` keyword
-"""""""""""""""""""""""
-
-When Spack variants and configure flags do not correspond one-to-one, the
-``variant`` keyword can be passed to ``with_or_without`` and
-``enable_or_disable``. For example:
-
-.. code-block:: python
-
-   variant('debug_tools', default=False)
-   config_args += self.enable_or_disable('debug-tools', variant='debug_tools')
-
-Or when one variant controls multiple flags:
-
-.. code-block:: python
-
-   variant('debug_tools', default=False)
-   config_args += self.with_or_without('memchecker', variant='debug_tools')
-   config_args += self.with_or_without('profiler', variant='debug_tools')
-
-
 """"""""""""""""""""
-Conditional variants
-""""""""""""""""""""
-
-When a variant is conditional and its condition is not met on the concrete spec, the
-``with_or_without`` and ``enable_or_disable`` methods will simply return an empty list.
-
-For example:
-
-.. code-block:: python
-
-   variant('profiler', when='@2.0:')
-   config_args += self.with_or_without('profiler)
-
-will neither add ``--with-profiler`` nor ``--without-profiler`` when the version is
-below ``2.0``.
-
-""""""""""""""""""""
-Activation overrides
+activation overrides
 """"""""""""""""""""

 Finally, the behavior of either ``with_or_without`` or
--- a/lib/spack/docs/build_systems/cmakepackage.rst
+++ b/lib/spack/docs/build_systems/cmakepackage.rst
@@ -145,20 +145,6 @@ and without the :meth:`~spack.build_systems.cmake.CMakePackage.define` and

       return args

-Spack supports CMake defines from conditional variants too. Whenever the condition on
-the variant is not met, ``define_from_variant()`` will simply return an empty string,
-and CMake simply ignores the empty command line argument. For example the following
-
-.. code-block:: python
-
-   variant('example', default=True, when='@2.0:')
-
-   def cmake_args(self):
-      return [self.define_from_variant('EXAMPLE', 'example')]
-
-will generate ``'cmake' '-DEXAMPLE=ON' ...`` when `@2.0: +example` is met, but will
-result in ``'cmake' '' ...`` when the spec version is below ``2.0``.
-

 ^^^^^^^^^^
 Generators
--- a/lib/spack/docs/build_systems/pythonpackage.rst
+++ b/lib/spack/docs/build_systems/pythonpackage.rst
@@ -125,15 +125,12 @@ The zip file will not contain a ``setup.py``, but it will contain a
 ``METADATA`` file which contains all the information you need to
 write a ``package.py`` build recipe.

-.. _pypi:
-
 ^^^^
 PyPI
 ^^^^

-The vast majority of Python packages are hosted on PyPI (The Python
-Package Index), which is :ref:`preferred over GitHub <pypi-vs-github>`
-for downloading packages. ``pip`` only supports packages hosted on PyPI, making
+The vast majority of Python packages are hosted on PyPI - The Python
+Package Index. ``pip`` only supports packages hosted on PyPI, making
 it the only option for developers who want a simple installation.
 Search for "PyPI <package-name>" to find the download page. Note that
 some pages are versioned, and the first result may not be the newest
@@ -220,7 +217,6 @@ try to extract the wheel:

   version('1.11.0', sha256='d8c9d24ea90457214d798b0d922489863dad518adde3638e08ef62de28fb183a', expand=False)

-.. _pypi-vs-github:

 """""""""""""""
 PyPI vs. GitHub
@@ -267,9 +263,6 @@ location, but PyPI is preferred for the following reasons:
   PyPI is nice because it makes it physically impossible to
   re-release the same version of a package with a different checksum.

-Use the :ref:`pypi attribute <pypi>` to facilitate construction of PyPI package
-references.
-
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 Build system dependencies
 ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -343,7 +336,7 @@ This would be translated to:
 .. code-block:: python

   extends('python')
-   depends_on('python@3.5:3', type=('build', 'run'))
+   depends_on('python@3.5:3.999', type=('build', 'run'))


 Many ``setup.py`` or ``setup.cfg`` files also contain information like::
@@ -575,7 +568,7 @@ check the ``METADATA`` file for lines like::
 Lines that use ``Requires-Dist`` are similar to ``install_requires``.
 Lines that use ``Provides-Extra`` are similar to ``extra_requires``,
 and you can add a variant for those dependencies. The ``~=1.11.0``
-syntax is equivalent to ``1.11.0:1.11``.
+syntax is equivalent to ``1.11.0:1.11.999``.

 """"""""""
 setuptools
@@ -716,7 +709,7 @@ The package may have its own unit or regression tests. Spack can
 run these tests during the installation by adding phase-appropriate
 test methods.

-For example, ``py-numpy`` adds the following as a check to run
+For example, ``py-numpy`` adds the following as a check to run 
 after the ``install`` phase:

 .. code-block:: python
--- a/lib/spack/docs/conf.py
+++ b/lib/spack/docs/conf.py
@@ -30,7 +30,6 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 sys.path.insert(0, os.path.abspath('_spack_root/lib/spack/external'))
-sys.path.insert(0, os.path.abspath('_spack_root/lib/spack/external/pytest-fallback'))

 if sys.version_info[0] < 3:
    sys.path.insert(
--- a/lib/spack/docs/config_yaml.rst
+++ b/lib/spack/docs/config_yaml.rst
@@ -259,16 +259,3 @@ and ld.so will ONLY search for dependencies in the ``RUNPATH`` of
 the loading object.

 DO NOT MIX the two options within the same install tree.
-
----------------------
-``terminal_title``
----------------------
-
-By setting this option to ``true``, Spack will update the terminal's title to
-provide information about its current progress as well as the current and
-total package numbers.
-
-To work properly, this requires your terminal to reset its title after
-Spack has finished its work, otherwise Spack's status information will
-remain in the terminal's title indefinitely. Most terminals should already
-be set up this way and clear Spack's status information.
--- a/lib/spack/docs/configuration.rst
+++ b/lib/spack/docs/configuration.rst
@@ -402,15 +402,12 @@ Spack-specific variables

 Spack understands several special variables. These are:

-* ``$env``: name of the currently active :ref:`environment <environments>`
 * ``$spack``: path to the prefix of this Spack installation
 * ``$tempdir``: default system temporary directory (as specified in
  Python's `tempfile.tempdir
  <https://docs.python.org/2/library/tempfile.html#tempfile.tempdir>`_
  variable.
 * ``$user``: name of the current user
-* ``$user_cache_path``: user cache directory (``~/.spack`` unless
-  :ref:`overridden <local-config-overrides>`)

 Note that, as with shell variables, you can write these as ``$varname``
 or with braces to distinguish the variable from surrounding characters:
@@ -565,39 +562,3 @@ built in and are not overridden by a configuration file. The
 command line. ``dirty`` and ``install_tree`` come from the custom
 scopes ``./my-scope`` and ``./my-scope-2``, and all other configuration
 options come from the default configuration files that ship with Spack.
-
-.. _local-config-overrides:
-
------------------------------
-Overriding Local Configuration
------------------------------
-
-Spack's ``system`` and ``user`` scopes provide ways for administrators and users to set
-global defaults for all Spack instances, but for use cases where one wants a clean Spack
-installation, these scopes can be undesirable. For example, users may want to opt out of
-global system configuration, or they may want to ignore their own home directory
-settings when running in a continuous integration environment.
-
-Spack also, by default, keeps various caches and user data in ``~/.spack``, but
-users may want to override these locations.
-
-Spack provides three environment variables that allow you to override or opt out of
-configuration locations:
-
-* ``SPACK_USER_CONFIG_PATH``: Override the path to use for the
-  ``user`` scope (``~/.spack`` by default).
-* ``SPACK_SYSTEM_CONFIG_PATH``: Override the path to use for the
-  ``system`` scope (``/etc/spack`` by default).
-* ``SPACK_DISABLE_LOCAL_CONFIG``: set this environment variable to completely disable
-  **both** the system and user configuration directories. Spack will only consider its
-  own defaults and ``site`` configuration locations.
-
-And one that allows you to move the default cache location:
-
-* ``SPACK_USER_CACHE_PATH``: Override the default path to use for user data
-  (misc_cache, tests, reports, etc.)
-
-With these settings, if you want to isolate Spack in a CI environment, you can do this::
-
-  export SPACK_DISABLE_LOCAL_CONFIG=true
-  export SPACK_USER_CACHE_PATH=/tmp/spack
--- a/lib/spack/docs/containers.rst
+++ b/lib/spack/docs/containers.rst
@@ -126,12 +126,12 @@ are currently supported are summarized in the table below:
   * - Ubuntu 18.04
     - ``ubuntu:18.04``
     - ``spack/ubuntu-bionic``
+   * - CentOS 6
+     - ``centos:6``
+     - ``spack/centos6``
   * - CentOS 7
     - ``centos:7``
     - ``spack/centos7``
-   * - openSUSE Leap
-     - ``opensuse/leap``
-     - ``spack/leap15``

 All the images are tagged with the corresponding release of Spack:

@@ -200,7 +200,7 @@ Setting Base Images

 The ``images`` subsection is used to select both the image where
 Spack builds the software and the image where the built software
-is installed. This attribute can be set in different ways and
+is installed. This attribute can be set in two different ways and
 which one to use depends on the use case at hand.

 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -260,54 +260,10 @@ software is respectively built and installed:

   ENTRYPOINT ["/bin/bash", "--rcfile", "/etc/profile", "-l"]

-This is the simplest available method of selecting base images, and we advise
+This method of selecting base images is the simplest of the two, and we advise
 to use it whenever possible. There are cases though where using Spack official
-images is not enough to fit production needs. In these situations users can
-extend the recipe to start with the bootstrapping of Spack at a certain pinned
-version or manually select which base image to start from in the recipe,
-as we'll see next.
-
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-Use a Bootstrap Stage for Spack
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-In some cases users may want to pin the commit sha that is used for Spack, to ensure later
-reproducibility, or start from a fork of the official Spack repository to try a bugfix or
-a feature in the early stage of development. This is possible by being just a little more
-verbose when specifying information about Spack in the ``spack.yaml`` file:
-
-.. code-block:: yaml
-
-   images:
-     os: amazonlinux:2
-     spack:
-       # URL of the Spack repository to be used in the container image
-       url: <to-use-a-fork>
-       # Either a commit sha, a branch name or a tag
-       ref: <sha/tag/branch>
-       # If true turn a branch name or a tag into the corresponding commit
-       # sha at the time of recipe generation
-       resolve_sha: <true/false>
-
-``url`` specifies the URL from which to clone Spack and defaults to https://github.com/spack/spack.
-The ``ref`` attribute can be either a commit sha, a branch name or a tag. The default value in
-this case is to use the ``develop`` branch, but it may change in the future to point to the latest stable
-release. Finally ``resolve_sha`` transform branch names or tags into the corresponding commit
-shas at the time of recipe generation, to allow for a greater reproducibility of the results
-at a later time.
-
-The list of operating systems that can be used to bootstrap Spack can be
-obtained with:
-
-.. command-output:: spack containerize --list-os
-
-.. note::
-
-   The ``resolve_sha`` option uses ``git rev-parse`` under the hood and thus it requires
-   to checkout the corresponding Spack repository in a temporary folder before generating
-   the recipe. Recipe generation may take longer when this option is set to true because
-   of this additional step.
-
+images is not enough to fit production needs. In these situations users can manually
+select which base image to start from in the recipe, as we'll see next.

 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Use Custom Images Provided by Users
@@ -459,18 +415,6 @@ to customize the generation of container recipes:
     - Version of Spack use in the ``build`` stage
     - Valid tags for ``base:image``
     - Yes, if using constrained selection of base images
-   * - ``images:spack:url``
-     - Repository from which Spack is cloned
-     - Any fork of Spack
-     - No
-   * - ``images:spack:ref``
-     - Reference for the checkout of Spack
-     - Either a commit sha, a branch name or a tag
-     - No
-   * - ``images:spack:resolve_sha``
-     - Resolve branches and tags in ``spack.yaml`` to commits in the generated recipe
-     - True or False (default: False)
-     - No
   * - ``images:build``
     - Image to be used in the ``build`` stage
     - Any valid container image
--- a/lib/spack/docs/contribution_guide.rst
+++ b/lib/spack/docs/contribution_guide.rst
@@ -71,7 +71,7 @@ locally to speed up the review process.
   new release that is causing problems. If this is the case, please file an issue.


-We currently test against Python 2.7 and 3.5-3.9 on both macOS and Linux and
+We currently test against Python 2.6, 2.7, and 3.5-3.7 on both macOS and Linux and
 perform 3 types of tests:

 .. _cmd-spack-unit-test:
@@ -338,6 +338,15 @@ Once all of the dependencies are installed, you can try building the documentati
 If you see any warning or error messages, you will have to correct those before
 your PR is accepted.

+.. note::
+
+   There is also a ``run-doc-tests`` script in ``share/spack/qa``. The only
+   difference between running this script and running ``make`` by hand is that
+   the script will exit immediately if it encounters an error or warning. This
+   is necessary for CI. If you made a lot of documentation changes, it is
+   much quicker to run ``make`` by hand so that you can see all of the warnings
+   at once.
+
 If you are editing the documentation, you should obviously be running the
 documentation tests. But even if you are simply adding a new package, your
 changes could cause the documentation tests to fail:
--- a/lib/spack/docs/developer_guide.rst
+++ b/lib/spack/docs/developer_guide.rst
@@ -210,6 +210,15 @@ Spec-related modules
     but compilers aren't fully integrated with the build process
     yet.

+:mod:`spack.architecture`
+  :func:`architecture.default_arch <spack.architecture.default_arch>` is used
+  to determine the host architecture while building.
+
+  .. warning::
+
+     Not yet implemented.  Should eventually have architecture
+     descriptions for cross-compiling.
+
 ^^^^^^^^^^^^^^^^^
 Build environment
 ^^^^^^^^^^^^^^^^^
@@ -671,13 +680,6 @@ If you need to write a hook that is relevant to a failure within a build
 process, you would want to instead use ``on_phase_failure``.


-"""""""""""""""""""""""""""
-``on_install_cancel(spec)``
-"""""""""""""""""""""""""""
-
-The same, but triggered if a spec install is cancelled for any reason.
-
-
 """""""""""""""""""""""""""""""""""""""""""""""
 ``on_phase_success(pkg, phase_name, log_file)``
 """""""""""""""""""""""""""""""""""""""""""""""
@@ -1184,10 +1186,6 @@ completed, the steps to make the major release are:
   If CI is not passing, submit pull requests to ``develop`` as normal
   and keep rebasing the release branch on ``develop`` until CI passes.

-#. Make sure the entire documentation is up to date. If documentation
-   is outdated submit pull requests to ``develop`` as normal
-   and keep rebasing the release branch on ``develop``.
-
 #. Follow the steps in :ref:`publishing-releases`.

 #. Follow the steps in :ref:`merging-releases`.
--- a/lib/spack/docs/getting_started.rst
+++ b/lib/spack/docs/getting_started.rst
@@ -35,7 +35,7 @@ Getting Spack is easy.  You can clone it from the `github repository

 .. code-block:: console

-   $ git clone -c feature.manyFiles=true https://github.com/spack/spack.git
+   $ git clone https://github.com/spack/spack.git

 This will create a directory called ``spack``.

@@ -88,71 +88,74 @@ the environment.
 Bootstrapping clingo
 ^^^^^^^^^^^^^^^^^^^^

-Spack uses ``clingo`` under the hood to resolve optimal versions and variants of
-dependencies when installing a package. Since ``clingo`` itself is a binary,
-Spack has to install it on initial use, which is called bootstrapping.
-
-Spack provides two ways of bootstrapping ``clingo``: from pre-built binaries
-(default), or from sources. The fastest way to get started is to bootstrap from
-pre-built binaries.
-
-.. note::
-
-   When bootstrapping from pre-built binaries, Spack currently requires 
-   ``patchelf`` on Linux and ``otool`` on macOS. If ``patchelf`` is not in the
-   ``PATH``, Spack will build it from sources, and a C++ compiler is required.
-
-The first time you concretize a spec, Spack will bootstrap in the background:
+Spack supports using ``clingo`` as an external solver to compute which software
+needs to be installed. The default configuration allows Spack to install
+``clingo`` from a public buildcache, created by a Github Action workflow. In this
+case the bootstrapping procedure is transparent to the user, except for a
+slightly long waiting time on the first concretization of a spec:

 .. code-block:: console

-   $ time spack spec zlib
-   Input spec
-   --------------------------------
-   zlib
+   $ spack find -b
+   ==> Showing internal bootstrap store at "/home/spack/.spack/bootstrap/store"
+   ==> 0 installed packages

-   Concretized
-   --------------------------------
-   zlib@1.2.11%gcc@7.5.0+optimize+pic+shared arch=linux-ubuntu18.04-zen
+   $ time spack solve zlib
+   ==> Best of 2 considered solutions.
+   ==> Optimization Criteria:
+     Priority  Criterion                                 Value
+     1         deprecated versions used                      0
+     2         version weight                                0
+     3         number of non-default variants (roots)        0
+     4         multi-valued variants                         0
+     5         preferred providers for roots                 0
+     6         number of non-default variants (non-roots)    0
+     7         preferred providers (non-roots)               0
+     8         compiler mismatches                           0
+     9         version badness                               0
+     10        count of non-root multi-valued variants       0
+     11        non-preferred compilers                       0
+     12        target mismatches                             0
+     13        non-preferred targets                         0

-   real	0m20.023s
-   user	0m18.351s
-   sys	0m0.784s
+   zlib@1.2.11%gcc@11.1.0+optimize+pic+shared arch=linux-ubuntu18.04-broadwell
+
+   real	0m30,618s
+   user	0m27,278s
+   sys	0m1,549s

 After this command you'll see that ``clingo`` has been installed for Spack's own use:

 .. code-block:: console

   $ spack find -b
-   ==> Showing internal bootstrap store at "/root/.spack/bootstrap/store"
-   ==> 3 installed packages
+   ==> Showing internal bootstrap store at "/home/spack/.spack/bootstrap/store"
+   ==> 2 installed packages
   -- linux-rhel5-x86_64 / gcc@9.3.0 -------------------------------
   clingo-bootstrap@spack  python@3.6

-   -- linux-ubuntu18.04-zen / gcc@7.5.0 ----------------------------
-   patchelf@0.13
-
 Subsequent calls to the concretizer will then be much faster:

 .. code-block:: console

-   $ time spack spec zlib
+   $ time spack solve zlib
   [ ... ]
-   real	0m0.490s
-   user	0m0.431s
-   sys	0m0.041s
+   real	0m1,222s
+   user	0m1,146s
+   sys	0m0,059s

-
-If for security concerns you cannot bootstrap ``clingo`` from pre-built
-binaries, you have to mark this bootstrapping method as untrusted. This makes
-Spack fall back to bootstrapping from sources:
+If for security or for other reasons you don't want to or can't install precompiled
+binaries, Spack can fall-back to bootstrap ``clingo`` from source files. To forbid
+Spack from retrieving binaries from the bootstrapping buildcache, the following
+command must be given:

 .. code-block:: console

   $ spack bootstrap untrust github-actions
   ==> "github-actions" is now untrusted and will not be used for bootstrapping

-You can verify that the new settings are effective with:
+since an "untrusted" way of bootstrapping software will not be considered
+by Spack. You can verify the new settings are effective with:

 .. code-block:: console

@@ -178,25 +181,33 @@ You can verify that the new settings are effective with:
     Description:
       Specs built from sources by Spack. May take a long time.

-.. note::
-
-   When bootstrapping from sources, Spack requires a full install of Python
-   including header files (e.g. ``python3-dev`` on Debian), and a compiler
-   with support for C++14 (GCC on Linux, Apple Clang on macOS) and static C++
-   standard libraries on Linux.
-
-Spack will build the required software on the first request to concretize a spec:
+When bootstrapping from sources, Spack requires a compiler with support
+for C++14 (GCC on ``linux``, Apple Clang on ``darwin``) and static C++
+standard libraries on ``linux``. Spack will build the required software
+on the first request to concretize a spec:

 .. code-block:: console

-   $ spack spec zlib
+   $ spack solve zlib
   [+] /usr (external bison-3.0.4-wu5pgjchxzemk5ya2l3ddqug2d7jv6eb)
   [+] /usr (external cmake-3.19.4-a4kmcfzxxy45mzku4ipmj5kdiiz5a57b)
   [+] /usr (external python-3.6.9-x4fou4iqqlh5ydwddx3pvfcwznfrqztv)
   ==> Installing re2c-1.2.1-e3x6nxtk3ahgd63ykgy44mpuva6jhtdt
   [ ... ]
+   ==> Optimization: [0, 0, 0, 0, 0, 1, 0, 0, 0]
   zlib@1.2.11%gcc@10.1.0+optimize+pic+shared arch=linux-ubuntu18.04-broadwell

+.. tip::
+
+   If you want to speed-up bootstrapping ``clingo`` from sources, you may try to
+   search for ``cmake`` and ``bison`` on your system:
+
+   .. code-block:: console
+
+      $ spack external find cmake bison
+      ==> The following specs have been detected on this system and added to /home/spack/.spack/packages.yaml
+      bison@3.0.4  cmake@3.19.4
+
 """""""""""""""""""
 The Bootstrap Store
 """""""""""""""""""
--- a/lib/spack/docs/index.rst
+++ b/lib/spack/docs/index.rst
@@ -39,7 +39,7 @@ package:

 .. code-block:: console

-   $ git clone -c feature.manyFiles=true https://github.com/spack/spack.git
+   $ git clone https://github.com/spack/spack.git
   $ cd spack/bin
   $ ./spack install libelf

--- a/lib/spack/docs/module_file_support.rst
+++ b/lib/spack/docs/module_file_support.rst
@@ -213,18 +213,6 @@ location). The set ``my_custom_lmod_modules`` will install its lmod
 modules to ``/path/to/install/custom/lmod/modules`` (and still install
 its tcl modules, if any, to the default location).

-By default, an architecture-specific directory is added to the root
-directory. A module set may override that behavior by setting the
-``arch_folder`` config value to ``False``.
-
-.. code-block:: yaml
-
-   modules:
-     default:
-       roots:
-         tcl: /path/to/install/tcl/modules
-       arch_folder: false
-
 Obviously, having multiple module sets install modules to the default
 location could be confusing to users of your modules. In the next
 section, we will discuss enabling and disabling module types (module
@@ -273,30 +261,29 @@ of the installed software. For instance, in the snippet below:
 .. code-block:: yaml

   modules:
-     default:
-       tcl:
-         # The keyword `all` selects every package
-         all:
-           environment:
-             set:
-               BAR: 'bar'
-         # This anonymous spec selects any package that
-         # depends on openmpi. The double colon at the
-         # end clears the set of rules that matched so far.
-         ^openmpi::
-           environment:
-             set:
-               BAR: 'baz'
-         # Selects any zlib package
-         zlib:
-           environment:
-             prepend_path:
-               LD_LIBRARY_PATH: 'foo'
-         # Selects zlib compiled with gcc@4.8
-         zlib%gcc@4.8:
-           environment:
-             unset:
-             - FOOBAR
+     tcl:
+       # The keyword `all` selects every package
+       all:
+         environment:
+           set:
+             BAR: 'bar'
+       # This anonymous spec selects any package that
+       # depends on openmpi. The double colon at the
+       # end clears the set of rules that matched so far.
+       ^openmpi::
+         environment:
+           set:
+             BAR: 'baz'
+       # Selects any zlib package
+       zlib:
+         environment:
+           prepend_path:
+             LD_LIBRARY_PATH: 'foo'
+       # Selects zlib compiled with gcc@4.8
+       zlib%gcc@4.8:
+         environment:
+           unset:
+           - FOOBAR

 you are instructing Spack to set the environment variable ``BAR=bar`` for every module,
 unless the associated spec satisfies ``^openmpi`` in which case ``BAR=baz``.
@@ -323,10 +310,9 @@ your system. If you write a configuration file like:
 .. code-block:: yaml

   modules:
-     default:
-       tcl:
-         whitelist: ['gcc', 'llvm']  # Whitelist will have precedence over blacklist
-         blacklist: ['%gcc@4.4.7']   # Assuming gcc@4.4.7 is the system compiler
+     tcl:
+       whitelist: ['gcc', 'llvm']  # Whitelist will have precedence over blacklist
+       blacklist: ['%gcc@4.4.7']   # Assuming gcc@4.4.7 is the system compiler

 you will prevent the generation of module files for any package that
 is compiled with ``gcc@4.4.7``, with the only exception of any ``gcc``
@@ -351,9 +337,8 @@ shows how to set hash length in the module file names:
 .. code-block:: yaml

   modules:
-     default:
-       tcl:
-         hash_length: 7
+     tcl:
+       hash_length: 7

 To help make module names more readable, and to help alleviate name conflicts
 with a short hash, one can use the ``suffixes`` option in the modules
@@ -363,12 +348,11 @@ For instance, the following config options,
 .. code-block:: yaml

   modules:
-     default:
-       tcl:
-         all:
-           suffixes:
-             ^python@2.7.12: 'python-2.7.12'
-             ^openblas: 'openblas'
+     tcl:
+       all:
+         suffixes:
+           ^python@2.7.12: 'python-2.7.12'
+           ^openblas: 'openblas'

 will add a ``python-2.7.12`` version string to any packages compiled with
 python matching the spec, ``python@2.7.12``. This is useful to know which
@@ -383,11 +367,10 @@ covered in :ref:`adding_projections_to_views`.
 .. code-block:: yaml

  modules:
-    default:
-      tcl:
-        projections:
-          all: '{name}/{version}-{compiler.name}-{compiler.version}-module'
-          ^mpi: '{name}/{version}-{^mpi.name}-{^mpi.version}-{compiler.name}-{compiler.version}-module'
+    tcl:
+      projections:
+        all: '{name}/{version}-{compiler.name}-{compiler.version}-module'
+        ^mpi: '{name}/{version}-{^mpi.name}-{^mpi.version}-{compiler.name}-{compiler.version}-module'

 will create module files that are nested in directories by package
 name, contain the version and compiler name and version, and have the
@@ -408,16 +391,15 @@ that are already in the LMod hierarchy.
     .. code-block:: yaml

        modules:
-          default:
-            enable:
-              - tcl
-            tcl:
-              projections:
-                all: '{name}/{version}-{compiler.name}-{compiler.version}'
-              all:
-                conflict:
-                  - '{name}'
-                  - 'intel/14.0.1'
+          enable:
+            - tcl
+          tcl:
+            projections:
+              all: '{name}/{version}-{compiler.name}-{compiler.version}'
+            all:
+              conflict:
+                - '{name}'
+                - 'intel/14.0.1'

     will create module files that will conflict with ``intel/14.0.1`` and with the
     base directory of the same module, effectively preventing the possibility to
@@ -437,17 +419,16 @@ that are already in the LMod hierarchy.
     .. code-block:: yaml

       modules:
-         default:
-           enable:
-             - lmod
-           lmod:
-             core_compilers:
-               - 'gcc@4.8'
-             core_specs:
-               - 'python'
-             hierarchy:
-               - 'mpi'
-               - 'lapack'
+         enable:
+           - lmod
+         lmod:
+           core_compilers:
+             - 'gcc@4.8'
+           core_specs:
+             - 'python'
+           hierarchy:
+             - 'mpi'
+             - 'lapack'

     that will generate a hierarchy in which the ``lapack`` and ``mpi`` layer can be switched
     independently. This allows a site to build the same libraries or applications against different
@@ -468,36 +449,6 @@ that are already in the LMod hierarchy.
   For hierarchies that are deeper than three layers ``lmod spider`` may have some issues.
   See `this discussion on the LMod project <https://github.com/TACC/Lmod/issues/114>`_.

-""""""""""""""""""""""
-Select default modules
-""""""""""""""""""""""
-
-By default, when multiple modules of the same name share a directory,
-the highest version number will be the default module. This behavior
-of the ``module`` command can be overridden with a symlink named
-``default`` to the desired default module. If you wish to configure
-default modules with Spack, add a ``defaults`` key to your modules
-configuration:
-
-.. code-block:: yaml
-
-  modules:
-    my-module-set:
-      tcl:
-        defaults:
-        - gcc@10.2.1
-        - hdf5@1.2.10+mpi+hl%gcc
-
-These defaults may be arbitrarily specific. For any package that
-satisfies a default, Spack will generate the module file in the
-appropriate path, and will generate a default symlink to the module
-file as well.
-
-.. warning:: 
-  If Spack is configured to generate multiple default packages in the
-  same directory, the last modulefile to be generated will be the
-  default module.
-
 .. _customize-env-modifications:

 """""""""""""""""""""""""""""""""""
@@ -598,12 +549,11 @@ do so by using the environment blacklist:
 .. code-block:: yaml

   modules:
-     default:
-       tcl:
-         all:
-           filter:
-             # Exclude changes to any of these variables
-             environment_blacklist: ['CPATH', 'LIBRARY_PATH']
+     tcl:
+       all:
+         filter:
+           # Exclude changes to any of these variables
+           environment_blacklist: ['CPATH', 'LIBRARY_PATH']

 The configuration above will generate module files that will not contain
 modifications to either ``CPATH`` or ``LIBRARY_PATH``.
@@ -622,10 +572,9 @@ activated using ``spack activate``:
 .. code-block:: yaml

   modules:
-     default:
-       tcl:
-         ^python:
-           autoload: 'direct'
+     tcl:
+       ^python:
+         autoload: 'direct'

 The configuration file above will produce module files that will
 load their direct dependencies if the package installed depends on ``python``.
@@ -642,10 +591,9 @@ The allowed values for the ``autoload`` statement are either ``none``,
  .. code-block:: yaml

     modules:
-       default:
-         lmod:
-           all:
-             autoload: 'direct'
+       lmod:
+         all:
+           autoload: 'direct'

 .. note::
  TCL prerequisites
--- a/lib/spack/docs/packaging_guide.rst
+++ b/lib/spack/docs/packaging_guide.rst
@@ -695,23 +695,20 @@ example, ``py-sphinx-rtd-theme@0.1.10a0``.  In this case, numbers are
 always considered to be "newer" than letters.  This is for consistency
 with `RPM <https://bugzilla.redhat.com/show_bug.cgi?id=50977>`_.

-Spack versions may also be arbitrary non-numeric strings, for example
-``@develop``, ``@master``, ``@local``.
+Spack versions may also be arbitrary non-numeric strings; any string
+here will suffice; for example, ``@develop``, ``@master``, ``@local``.
+Versions are compared as follows. First, a version string is split into
+multiple fields based on delimiters such as ``.``, ``-`` etc. Then
+matching fields are compared using the rules below:

-The order on versions is defined as follows. A version string is split
-into a list of components based on delimiters such as ``.``, ``-`` etc. 
-Lists are then ordered lexicographically, where components are ordered
-as follows:
+#. The following develop-like strings are greater (newer) than all
+   numbers and are ordered as ``develop > main > master > head > trunk``.

-#. The following special strings are considered larger than any other
-   numeric or non-numeric version component, and satisfy the following
-   order between themselves: ``develop > main > master > head > trunk``.
+#. Numbers are all less than the chosen develop-like strings above,
+   and are sorted numerically.

-#. Numbers are ordered numerically, are less than special strings, and
-   larger than other non-numeric components.
-
-#. All other non-numeric components are less than numeric components,
-   and are ordered alphabetically.
+#. All other non-numeric versions are less than numeric versions, and
+   are sorted alphabetically.

 The logic behind this sort order is two-fold:

@@ -732,7 +729,7 @@ Version selection
 When concretizing, many versions might match a user-supplied spec.
 For example, the spec ``python`` matches all available versions of the
 package ``python``.  Similarly, ``python@3:`` matches all versions of
-Python 3 and above.  Given a set of versions that match a spec, Spack
+Python3.  Given a set of versions that match a spec, Spack
 concretization uses the following priorities to decide which one to
 use:

@@ -1422,60 +1419,6 @@ other similar operations:
            ).with_default('auto').with_non_feature_values('auto'),
        )

-^^^^^^^^^^^^^^^^^^^^
-Conditional Variants
-^^^^^^^^^^^^^^^^^^^^
-
-The variant directive accepts a ``when`` clause. The variant will only
-be present on specs that otherwise satisfy the spec listed as the
-``when`` clause. For example, the following class has a variant
-``bar`` when it is at version 2.0 or higher.
-
-.. code-block:: python
-
-   class Foo(Package):
-       ...
-       variant('bar', default=False, when='@2.0:', description='help message')
-
-The ``when`` clause follows the same syntax and accepts the same
-values as the ``when`` argument of
-:py:func:`spack.directives.depends_on`
-
-^^^^^^^^^^^^^^^^^^^
-Overriding Variants
-^^^^^^^^^^^^^^^^^^^
-
-Packages may override variants for several reasons, most often to
-change the default from a variant defined in a parent class or to
-change the conditions under which a variant is present on the spec.
-
-When a variant is defined multiple times, whether in the same package
-file or in a subclass and a superclass, the last definition is used
-for all attributes **except** for the ``when`` clauses. The ``when``
-clauses are accumulated through all invocations, and the variant is
-present on the spec if any of the accumulated conditions are
-satisfied.
-
-For example, consider the following package:
-
-.. code-block:: python
-
-   class Foo(Package):
-       ...
-       variant('bar', default=False, when='@1.0', description='help1')
-       variant('bar', default=True, when='platform=darwin', description='help2')
-       ...
-
-This package ``foo`` has a variant ``bar`` when the spec satisfies
-either ``@1.0`` or ``platform=darwin``, but not for other platforms at
-other versions. The default for this variant, when it is present, is
-always ``True``, regardless of which condition of the variant is
-satisfied. This allows packages to override variants in packages or
-build system classes from which they inherit, by modifying the variant
-values without modifying the ``when`` clause. It also allows a package
-to implement ``or`` semantics for a variant ``when`` clause by
-duplicating the variant definition.
-
 ------------------------------------
 Resources (expanding extra tarballs)
 ------------------------------------
@@ -2120,7 +2063,7 @@ Version ranges
 ^^^^^^^^^^^^^^

 Although some packages require a specific version for their dependencies,
-most can be built with a range of versions. For example, if you are
+most can be built with a range of version. For example, if you are
 writing a package for a legacy Python module that only works with Python
 2.4 through 2.6, this would look like:

@@ -2129,9 +2072,9 @@ writing a package for a legacy Python module that only works with Python
   depends_on('python@2.4:2.6')

 Version ranges in Spack are *inclusive*, so ``2.4:2.6`` means any version
-greater than or equal to ``2.4`` and up to and including any ``2.6.x``. If
-you want to specify that a package works with any version of Python 3 (or
-higher), this would look like:
+greater than or equal to ``2.4`` and up to and including ``2.6``. If you
+want to specify that a package works with any version of Python 3, this
+would look like:

 .. code-block:: python

@@ -2142,30 +2085,29 @@ requires Python 2, you can similarly leave out the lower bound:

 .. code-block:: python

-   depends_on('python@:2')
+   depends_on('python@:2.9')

 Notice that we didn't use ``@:3``. Version ranges are *inclusive*, so
-``@:3`` means "up to and including any 3.x version".
+``@:3`` means "up to and including 3".

-What if a package can only be built with Python 2.7? You might be
+What if a package can only be built with Python 2.6? You might be
 inclined to use:

 .. code-block:: python

-   depends_on('python@2.7')
+   depends_on('python@2.6')

 However, this would be wrong. Spack assumes that all version constraints
-are exact, so it would try to install Python not at ``2.7.18``, but
-exactly at ``2.7``, which is a non-existent version. The correct way to
-specify this would be:
+are absolute, so it would try to install Python at exactly ``2.6``. The
+correct way to specify this would be:

 .. code-block:: python

-   depends_on('python@2.7.0:2.7')
+   depends_on('python@2.6.0:2.6.999')

-A spec can contain a version list of ranges and individual versions
-separated by commas. For example, if you need Boost 1.59.0 or newer,
-but there are known issues with 1.64.0, 1.65.0, and 1.66.0, you can say:
+A spec can contain multiple version ranges separated by commas.
+For example, if you need Boost 1.59.0 or newer, but there are known
+issues with 1.64.0, 1.65.0, and 1.66.0, you can say:

 .. code-block:: python

@@ -2882,7 +2824,7 @@ is equivalent to:

   depends_on('elpa+openmp', when='+openmp+elpa')

-Constraints from nested context managers are also combined together, but they are rarely
+Constraints from nested context managers are also added together, but they are rarely
 needed or recommended.

 .. _install-method:
@@ -2943,7 +2885,7 @@ The package base class, usually specialized for a given build system, determines
 actual set of entities available for overriding.
 The classes that are currently provided by Spack are:

-+----------------------------------------------------------+----------------------------------+
+-------------------------=--------------------------------+----------------------------------+
 |     **Base Class**                                       |           **Purpose**            |
 +==========================================================+==================================+
 | :class:`~spack.package.Package`                          | General base class not           |
--- a/lib/spack/docs/pipelines.rst
+++ b/lib/spack/docs/pipelines.rst
@@ -48,9 +48,9 @@ or Amazon Elastic Kubernetes Service (`EKS <https://aws.amazon.com/eks>`_), thou
 topics are outside the scope of this document.

 Spack's pipelines are now making use of the
-`trigger <https://docs.gitlab.com/ee/ci/yaml/#trigger>`_ syntax to run
+`trigger <https://docs.gitlab.com/12.9/ee/ci/yaml/README.html#trigger>`_ syntax to run
 dynamically generated
-`child pipelines <https://docs.gitlab.com/ee/ci/pipelines/parent_child_pipelines.html>`_.
+`child pipelines <https://docs.gitlab.com/12.9/ee/ci/parent_child_pipelines.html>`_.
 Note that the use of dynamic child pipelines requires running Gitlab version
 ``>= 12.9``.

--- a/lib/spack/docs/repositories.rst
+++ b/lib/spack/docs/repositories.rst
@@ -335,7 +335,7 @@ merged YAML from all configuration files, use ``spack config get repos``:
   - ~/myrepo
   - $spack/var/spack/repos/builtin

-Note that, unlike ``spack repo list``, this does not include the
+mNote that, unlike ``spack repo list``, this does not include the
 namespace, which is read from each repo's ``repo.yaml``.

 ^^^^^^^^^^^^^^^^^^^^^
--- a/lib/spack/docs/requirements.txt
+++ b/lib/spack/docs/requirements.txt
@@ -5,6 +5,3 @@ sphinx>=3.4,!=4.1.2
 sphinxcontrib-programoutput
 sphinx-rtd-theme
 python-levenshtein
-# Restrict to docutils <0.17 to workaround a list rendering issue in sphinx.
-# https://stackoverflow.com/questions/67542699
-docutils <0.17
--- a/lib/spack/docs/spack.yaml
+++ b/lib/spack/docs/spack.yaml
@@ -17,7 +17,6 @@ spack:
  # Sphinx
  - "py-sphinx@3.4:4.1.1,4.1.3:"
  - py-sphinxcontrib-programoutput
-  - py-docutils@:0.16
  - py-sphinx-rtd-theme
  # VCS
  - git
--- a/lib/spack/docs/tables/system_prerequisites.csv
+++ b/lib/spack/docs/tables/system_prerequisites.csv
@@ -1,5 +1,5 @@
 Name, Supported Versions, Notes, Requirement Reason
-Python, 2.7/3.5-3.9, , Interpreter for Spack
+Python, 2.6/2.7/3.5-3.9, , Interpreter for Spack
 C/C++ Compilers, , , Building software
 make, , , Build software
 patch, , , Build software
@@ -15,4 +15,3 @@ gnupg2, , , Sign/Verify Buildcaches
 git, , , Manage Software Repositories
 svn, , Optional, Manage Software Repositories
 hg, , Optional, Manage Software Repositories
-Python header files, , Optional (e.g. ``python3-dev`` on Debian), Bootstrapping from sources
--- a/lib/spack/env/cc
+++ b/lib/spack/env/cc
@@ -1,5 +1,4 @@
-#!/bin/sh
-# shellcheck disable=SC2034  # evals in this script fool shellcheck
+#!/bin/bash
 #
 # Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
@@ -21,33 +20,25 @@
 #      -Wl,-rpath         arguments for dependency /lib directories.
 #

-# Reset IFS to the default: whitespace-separated lists. When we use
-# other separators, we set and reset it.
-unset IFS
-
-# Separator for lists whose names end with `_list`.
-# We pick the alarm bell character, which is highly unlikely to
-# conflict with anything. This is a literal bell character (which
-# we have to use since POSIX sh does not convert escape sequences
-# like '\a' outside of the format argument of `printf`).
-# NOTE: Depending on your editor this may look empty, but it is not.
-readonly lsep=''
-
 # This is an array of environment variables that need to be set before
 # the script runs. They are set by routines in spack.build_environment
 # as part of the package installation process.
-readonly params="\
-SPACK_ENV_PATH
-SPACK_DEBUG_LOG_DIR
-SPACK_DEBUG_LOG_ID
-SPACK_COMPILER_SPEC
-SPACK_CC_RPATH_ARG
-SPACK_CXX_RPATH_ARG
-SPACK_F77_RPATH_ARG
-SPACK_FC_RPATH_ARG
-SPACK_LINKER_ARG
-SPACK_SHORT_SPEC
-SPACK_SYSTEM_DIRS"
+parameters=(
+    SPACK_ENV_PATH
+    SPACK_DEBUG_LOG_DIR
+    SPACK_DEBUG_LOG_ID
+    SPACK_COMPILER_SPEC
+    SPACK_CC_RPATH_ARG
+    SPACK_CXX_RPATH_ARG
+    SPACK_F77_RPATH_ARG
+    SPACK_FC_RPATH_ARG
+    SPACK_TARGET_ARGS
+    SPACK_DTAGS_TO_ADD
+    SPACK_DTAGS_TO_STRIP
+    SPACK_LINKER_ARG
+    SPACK_SHORT_SPEC
+    SPACK_SYSTEM_DIRS
+)

 # Optional parameters that aren't required to be set

@@ -67,157 +58,60 @@ SPACK_SYSTEM_DIRS"
 # Test command is used to unit test the compiler script.
 #   SPACK_TEST_COMMAND

-# die MESSAGE
-# Print a message and exit with error code 1.
-die() {
-    echo "[spack cc] ERROR: $*"
+# die()
+# Prints a message and exits with error 1.
+function die {
+    echo "$@"
    exit 1
 }

-# empty VARNAME
-# Return whether the variable VARNAME is unset or set to the empty string.
-empty() {
-    eval "test -z \"\${$1}\""
-}
+# read input parameters into proper bash arrays.
+# SYSTEM_DIRS is delimited by :
+IFS=':' read -ra SPACK_SYSTEM_DIRS <<< "${SPACK_SYSTEM_DIRS}"

-# setsep LISTNAME
-# Set the global variable 'sep' to the separator for a list with name LISTNAME.
-# There are three types of lists:
-#   1. regular lists end with _list and are separated by $lsep
-#   2. directory lists end with _dirs/_DIRS/PATH(S) and are separated by ':'
-#   3. any other list is assumed to be separated by spaces: " "
-setsep() {
-    case "$1" in
-        *_dirs|*_DIRS|*PATH|*PATHS)
-            sep=':'
-            ;;
-        *_list)
-            sep="$lsep"
-            ;;
-        *)
-            sep=" "
-            ;;
-    esac
-}
+# SPACK_<LANG>FLAGS and SPACK_LDLIBS are split by ' '
+IFS=' ' read -ra SPACK_FFLAGS   <<< "$SPACK_FFLAGS"
+IFS=' ' read -ra SPACK_CPPFLAGS <<< "$SPACK_CPPFLAGS"
+IFS=' ' read -ra SPACK_CFLAGS   <<< "$SPACK_CFLAGS"
+IFS=' ' read -ra SPACK_CXXFLAGS <<< "$SPACK_CXXFLAGS"
+IFS=' ' read -ra SPACK_LDFLAGS  <<< "$SPACK_LDFLAGS"
+IFS=' ' read -ra SPACK_LDLIBS   <<< "$SPACK_LDLIBS"

-# prepend LISTNAME ELEMENT [SEP]
-#
-# Prepend ELEMENT to the list stored in the variable LISTNAME,
-# assuming the list is separated by SEP.
-# Handles empty lists and single-element lists.
-prepend() {
-    varname="$1"
-    elt="$2"
-
-    if empty "$varname"; then
-        eval "$varname=\"\${elt}\""
-    else
-        # Get the appropriate separator for the list we're appending to.
-        setsep "$varname"
-        eval "$varname=\"\${elt}${sep}\${$varname}\""
-    fi
-}
-
-# append LISTNAME ELEMENT [SEP]
-#
-# Append ELEMENT to the list stored in the variable LISTNAME,
-# assuming the list is separated by SEP.
-# Handles empty lists and single-element lists.
-append() {
-    varname="$1"
-    elt="$2"
-
-    if empty "$varname"; then
-        eval "$varname=\"\${elt}\""
-    else
-        # Get the appropriate separator for the list we're appending to.
-        setsep "$varname"
-        eval "$varname=\"\${$varname}${sep}\${elt}\""
-    fi
-}
-
-# extend LISTNAME1 LISTNAME2 [PREFIX]
-#
-# Append the elements stored in the variable LISTNAME2
-# to the list stored in LISTNAME1.
-# If PREFIX is provided, prepend it to each element.
-extend() {
-    # Figure out the appropriate IFS for the list we're reading.
-    setsep "$2"
-    if [ "$sep" != " " ]; then
-        IFS="$sep"
-    fi
-    eval "for elt in \${$2}; do append $1 \"$3\${elt}\"; done"
-    unset IFS
-}
-
-# preextend LISTNAME1 LISTNAME2 [PREFIX]
-#
-# Prepend the elements stored in the list at LISTNAME2
-# to the list at LISTNAME1, preserving order.
-# If PREFIX is provided, prepend it to each element.
-preextend() {
-    # Figure out the appropriate IFS for the list we're reading.
-    setsep "$2"
-    if [ "$sep" != " " ]; then
-        IFS="$sep"
-    fi
-
-    # first, reverse the list to prepend
-    _reversed_list=""
-    eval "for elt in \${$2}; do prepend _reversed_list \"$3\${elt}\"; done"
-
-    # prepend reversed list to preextend in order
-    IFS="${lsep}"
-    for elt in $_reversed_list; do prepend "$1" "$3${elt}"; done
-    unset IFS
-}
-
-# system_dir PATH
 # test whether a path is a system directory
-system_dir() {
-    IFS=':'  # SPACK_SYSTEM_DIRS is colon-separated
+function system_dir {
    path="$1"
-    for sd in $SPACK_SYSTEM_DIRS; do
-        if [ "${path}" = "${sd}" ] || [ "${path}" = "${sd}/" ]; then
+    for sd in "${SPACK_SYSTEM_DIRS[@]}"; do
+        if [ "${path}" == "${sd}" ] || [ "${path}" == "${sd}/" ]; then
            # success if path starts with a system prefix
-            unset IFS
            return 0
        fi
    done
-    unset IFS
    return 1  # fail if path starts no system prefix
 }

-# Fail with a clear message if the input contains any bell characters.
-if eval "[ \"\${*#*${lsep}}\" != \"\$*\" ]"; then
-    die "Compiler command line contains our separator ('${lsep}'). Cannot parse."
-fi
-
-# ensure required variables are set
-for param in $params; do
-    if eval "test -z \"\${${param}:-}\""; then
+for param in "${parameters[@]}"; do
+    if [[ -z ${!param+x} ]]; then
        die "Spack compiler must be run from Spack! Input '$param' is missing."
    fi
 done

 # Check if optional parameters are defined
 # If we aren't asking for debug flags, don't add them
-if [ -z "${SPACK_ADD_DEBUG_FLAGS:-}" ]; then
+if [[ -z ${SPACK_ADD_DEBUG_FLAGS+x} ]]; then
    SPACK_ADD_DEBUG_FLAGS="false"
 fi

 # SPACK_ADD_DEBUG_FLAGS must be true/false/custom
 is_valid="false"
 for param in "true" "false" "custom"; do
-  if [ "$param" = "$SPACK_ADD_DEBUG_FLAGS" ];  then
+  if [ "$param" == "$SPACK_ADD_DEBUG_FLAGS" ];  then
      is_valid="true"
  fi
 done

 # Exit with error if we are given an incorrect value
-if [ "$is_valid" = "false" ]; then
-    die "SPACK_ADD_DEBUG_FLAGS, if defined, must be one of 'true', 'false', or 'custom'."
+if [ "$is_valid" == "false" ]; then
+    die "SPACK_ADD_DEBUG_FLAGS, if defined, must be one of 'true' 'false' or 'custom'"
 fi

 # Figure out the type of compiler, the language, and the mode so that
@@ -234,7 +128,7 @@ fi
 #    ld      link
 #    ccld    compile & link

-command="${0##*/}"
+command=$(basename "$0")
 comp="CC"
 case "$command" in
    cpp)
@@ -248,7 +142,7 @@ case "$command" in
        lang_flags=C
        debug_flags="-g"
        ;;
-    c++|CC|g++|clang++|armclang++|icpc|icpx|dpcpp|pgc++|nvc++|xlc++|xlc++_r|FCC)
+    c++|CC|g++|clang++|armclang++|icpc|icpx|pgc++|nvc++|xlc++|xlc++_r|FCC)
        command="$SPACK_CXX"
        language="C++"
        comp="CXX"
@@ -280,7 +174,7 @@ esac
 # If any of the arguments below are present, then the mode is vcheck.
 # In vcheck mode, nothing is added in terms of extra search paths or
 # libraries.
-if [ -z "$mode" ] || [ "$mode" = ld ]; then
+if [[ -z $mode ]] || [[ $mode == ld ]]; then
    for arg in "$@"; do
        case $arg in
            -v|-V|--version|-dumpversion)
@@ -292,16 +186,16 @@ if [ -z "$mode" ] || [ "$mode" = ld ]; then
 fi

 # Finish setting up the mode.
-if [ -z "$mode" ]; then
+if [[ -z $mode ]]; then
    mode=ccld
    for arg in "$@"; do
-        if [ "$arg" = "-E" ]; then
+        if [[ $arg == -E ]]; then
            mode=cpp
            break
-        elif [ "$arg" = "-S" ]; then
+        elif [[ $arg == -S ]]; then
            mode=as
            break
-        elif [ "$arg" = "-c" ]; then
+        elif [[ $arg == -c ]]; then
            mode=cc
            break
        fi
@@ -328,46 +222,42 @@ dtags_to_strip="${SPACK_DTAGS_TO_STRIP}"
 linker_arg="${SPACK_LINKER_ARG}"

 # Set up rpath variable according to language.
-rpath="ERROR: RPATH ARG WAS NOT SET"
-eval "rpath=\${SPACK_${comp}_RPATH_ARG:?${rpath}}"
+eval rpath=\$SPACK_${comp}_RPATH_ARG

 # Dump the mode and exit if the command is dump-mode.
-if [ "$SPACK_TEST_COMMAND" = "dump-mode" ]; then
+if [[ $SPACK_TEST_COMMAND == dump-mode ]]; then
    echo "$mode"
    exit
 fi

-# If, say, SPACK_CC is set but SPACK_FC is not, we want to know. Compilers do not
-# *have* to set up Fortran executables, so we need to tell the user when a build is
-# about to attempt to use them unsuccessfully.
-if [ -z "$command" ]; then
-    die "Compiler '$SPACK_COMPILER_SPEC' does not have a $language compiler configured."
+# Check that at least one of the real commands was actually selected,
+# otherwise we don't know what to execute.
+if [[ -z $command ]]; then
+    die "ERROR: Compiler '$SPACK_COMPILER_SPEC' does not support compiling $language programs."
 fi

 #
 # Filter '.' and Spack environment directories out of PATH so that
 # this script doesn't just call itself
 #
-new_dirs=""
-IFS=':'
-for dir in $PATH; do
+IFS=':' read -ra env_path <<< "$PATH"
+IFS=':' read -ra spack_env_dirs <<< "$SPACK_ENV_PATH"
+spack_env_dirs+=("" ".")
+export PATH=""
+for dir in "${env_path[@]}"; do
    addpath=true
-    for spack_env_dir in $SPACK_ENV_PATH; do
-        case "${dir%%/}" in
-            "$spack_env_dir"|'.'|'')
-                addpath=false
-                break
-                ;;
-        esac
+    for env_dir in "${spack_env_dirs[@]}"; do
+        if [[ "${dir%%/}" == "$env_dir" ]]; then
+            addpath=false
+            break
+        fi
    done
-    if [ $addpath = true ]; then
-        append new_dirs "$dir"
+    if $addpath; then
+        export PATH="${PATH:+$PATH:}$dir"
    fi
 done
-unset IFS
-export PATH="$new_dirs"

-if [ "$mode" = vcheck ]; then
+if [[ $mode == vcheck ]]; then
    exec "${command}" "$@"
 fi

@@ -375,20 +265,16 @@ fi
 # It doesn't work with -rpath.
 # This variable controls whether they are added.
 add_rpaths=true
-if [ "$mode" = ld ] || [ "$mode" = ccld ]; then
-    if [ "${SPACK_SHORT_SPEC#*darwin}" != "${SPACK_SHORT_SPEC}" ]; then
-        for arg in "$@"; do
-            if [ "$arg" = "-r" ]; then
-                if [ "$mode" = ld ] || [ "$mode" = ccld ]; then
-                    add_rpaths=false
-                    break
-                fi
-            elif [ "$arg" = "-Wl,-r" ] && [ "$mode" = ccld ]; then
-                add_rpaths=false
-                break
-            fi
-        done
-    fi
+if [[ ($mode == ld || $mode == ccld) && "$SPACK_SHORT_SPEC" =~ "darwin" ]];
+then
+    for arg in "$@"; do
+        if [[ ($arg == -r && $mode == ld) ||
+              ($arg == -r && $mode == ccld) ||
+              ($arg == -Wl,-r && $mode == ccld) ]]; then
+            add_rpaths=false
+            break
+        fi
+    done
 fi

 # Save original command for debug logging
@@ -411,22 +297,17 @@ input_command="$*"
 # The libs variable is initialized here for completeness, and it is also
 # used later to inject flags supplied via `ldlibs` on the command
 # line. These come into the wrappers via SPACK_LDLIBS.
-
-# The loop below breaks up the command line into these lists of components.
-# The lists are all bell-separated to be as flexible as possible, as their
-# contents may come from the command line, from ' '-separated lists,
-# ':'-separated lists, etc.
-include_dirs_list=""
-lib_dirs_list=""
-rpath_dirs_list=""
-system_include_dirs_list=""
-system_lib_dirs_list=""
-system_rpath_dirs_list=""
-isystem_system_include_dirs_list=""
-isystem_include_dirs_list=""
-libs_list=""
-other_args_list=""
-
+#
+includes=()
+libdirs=()
+rpaths=()
+system_includes=()
+system_libdirs=()
+system_rpaths=()
+libs=()
+other_args=()
+isystem_system_includes=()
+isystem_includes=()

 while [ $# -ne 0 ]; do

@@ -446,32 +327,32 @@ while [ $# -ne 0 ]; do
            isystem_was_used=true
            if [ -z "$arg" ]; then shift; arg="$1"; fi
            if system_dir "$arg"; then
-                append isystem_system_include_dirs_list "$arg"
+                isystem_system_includes+=("$arg")
            else
-                append isystem_include_dirs_list "$arg"
+                isystem_includes+=("$arg")
            fi
            ;;
        -I*)
            arg="${1#-I}"
            if [ -z "$arg" ]; then shift; arg="$1"; fi
            if system_dir "$arg"; then
-                append system_include_dirs_list "$arg"
+                system_includes+=("$arg")
            else
-                append include_dirs_list "$arg"
+                includes+=("$arg")
            fi
            ;;
        -L*)
            arg="${1#-L}"
            if [ -z "$arg" ]; then shift; arg="$1"; fi
            if system_dir "$arg"; then
-                append system_lib_dirs_list "$arg"
+                system_libdirs+=("$arg")
            else
-                append lib_dirs_list "$arg"
+                libdirs+=("$arg")
            fi
            ;;
        -l*)
            # -loopopt=0 is generated erroneously in autoconf <= 2.69,
-            # and passed by ifx to the linker, which confuses it with a
+            # and passed by ifx to the linker, which confuses it with a 
            # library. Filter it out.
            # TODO: generalize filtering of args with an env var, so that
            # TODO: we do not have to special case this here.
@@ -482,76 +363,66 @@ while [ $# -ne 0 ]; do
            fi
            arg="${1#-l}"
            if [ -z "$arg" ]; then shift; arg="$1"; fi
-            append other_args_list "-l$arg"
+            other_args+=("-l$arg")
            ;;
        -Wl,*)
            arg="${1#-Wl,}"
            if [ -z "$arg" ]; then shift; arg="$1"; fi
-            case "$arg" in
-                -rpath=*)  rp="${arg#-rpath=}"  ;;
-                --rpath=*) rp="${arg#--rpath=}" ;;
-                -rpath,*)  rp="${arg#-rpath,}"  ;;
-                --rpath,*) rp="${arg#--rpath,}" ;;
-                -rpath|--rpath)
-                    shift; arg="$1"
-                    case "$arg" in
-                        -Wl,*)
-                            rp="${arg#-Wl,}"
-                            ;;
-                        *)
-                            die "-Wl,-rpath was not followed by -Wl,*"
-                            ;;
-                    esac
-                    ;;
-                "$dtags_to_strip")
-                    :  # We want to remove explicitly this flag
-                    ;;
-                *)
-                    append other_args_list "-Wl,$arg"
-                    ;;
-            esac
+            if [[ "$arg" = -rpath=* ]]; then
+                rp="${arg#-rpath=}"
+            elif [[ "$arg" = --rpath=* ]]; then
+                rp="${arg#--rpath=}"
+            elif [[ "$arg" = -rpath,* ]]; then
+                rp="${arg#-rpath,}"
+            elif [[ "$arg" = --rpath,* ]]; then
+                rp="${arg#--rpath,}"
+            elif [[ "$arg" =~ ^-?-rpath$ ]]; then
+                shift; arg="$1"
+                if [[ "$arg" != -Wl,* ]]; then
+                    die "-Wl,-rpath was not followed by -Wl,*"
+                fi
+                rp="${arg#-Wl,}"
+            elif [[ "$arg" = "$dtags_to_strip" ]] ; then
+                :  # We want to remove explicitly this flag
+            else
+                other_args+=("-Wl,$arg")
+            fi
            ;;
        -Xlinker,*)
            arg="${1#-Xlinker,}"
            if [ -z "$arg" ]; then shift; arg="$1"; fi
-
-            case "$arg" in
-                -rpath=*)  rp="${arg#-rpath=}"  ;;
-                --rpath=*) rp="${arg#--rpath=}" ;;
-                -rpath|--rpath)
-                    shift; arg="$1"
-                    case "$arg" in
-                        -Xlinker,*)
-                            rp="${arg#-Xlinker,}"
-                        ;;
-                        *)
-                            die "-Xlinker,-rpath was not followed by -Xlinker,*"
-                            ;;
-                    esac
-                    ;;
-                *)
-                    append other_args_list "-Xlinker,$arg"
-                    ;;
-            esac
+            if [[ "$arg" = -rpath=* ]]; then
+                rp="${arg#-rpath=}"
+            elif [[ "$arg" = --rpath=* ]]; then
+                rp="${arg#--rpath=}"
+            elif [[ "$arg" = -rpath  ]] || [[ "$arg" = --rpath ]]; then
+                shift; arg="$1"
+                if [[ "$arg" != -Xlinker,* ]]; then
+                    die "-Xlinker,-rpath was not followed by -Xlinker,*"
+                fi
+                rp="${arg#-Xlinker,}"
+            else
+                other_args+=("-Xlinker,$arg")
+            fi
            ;;
        -Xlinker)
-            if [ "$2" = "-rpath" ]; then
-                if [ "$3" != "-Xlinker" ]; then
+            if [[ "$2" == "-rpath" ]]; then
+                if [[ "$3" != "-Xlinker" ]]; then
                    die "-Xlinker,-rpath was not followed by -Xlinker,*"
                fi
                shift 3;
                rp="$1"
-            elif [ "$2" = "$dtags_to_strip" ]; then
+            elif [[ "$2" = "$dtags_to_strip" ]] ; then
                shift  # We want to remove explicitly this flag
            else
-                append other_args_list "$1"
+                other_args+=("$1")
            fi
            ;;
        *)
-            if [ "$1" = "$dtags_to_strip" ]; then
+            if [[ "$1" = "$dtags_to_strip" ]] ; then
                :  # We want to remove explicitly this flag
            else
-                append other_args_list "$1"
+                other_args+=("$1")
            fi
            ;;
    esac
@@ -559,9 +430,9 @@ while [ $# -ne 0 ]; do
    # test rpaths against system directories in one place.
    if [ -n "$rp" ]; then
        if system_dir "$rp"; then
-            append system_rpath_dirs_list "$rp"
+            system_rpaths+=("$rp")
        else
-            append rpath_dirs_list "$rp"
+            rpaths+=("$rp")
        fi
    fi
    shift
@@ -574,15 +445,16 @@ done
 # See the gmake manual on implicit rules for details:
 # https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html
 #
-flags_list=""
+flags=()

 # Add debug flags
-if [ "${SPACK_ADD_DEBUG_FLAGS}" = "true" ]; then
-    extend flags_list debug_flags
+if [ "${SPACK_ADD_DEBUG_FLAGS}" == "true" ]; then
+    flags=("${flags[@]}" "${debug_flags}")

 # If a custom flag is requested, derive from environment
-elif [ "$SPACK_ADD_DEBUG_FLAGS" = "custom" ]; then
-    extend flags_list SPACK_DEBUG_FLAGS
+elif [ "$SPACK_ADD_DEBUG_FLAGS" == "custom" ]; then
+    IFS=' ' read -ra SPACK_DEBUG_FLAGS <<< "$SPACK_DEBUG_FLAGS"
+    flags=("${flags[@]}" "${SPACK_DEBUG_FLAGS[@]}")
 fi

 # Fortran flags come before CPPFLAGS
@@ -590,8 +462,7 @@ case "$mode" in
    cc|ccld)
        case $lang_flags in
            F)
-                extend flags_list SPACK_FFLAGS
-                ;;
+                flags=("${flags[@]}" "${SPACK_FFLAGS[@]}") ;;
        esac
        ;;
 esac
@@ -599,8 +470,7 @@ esac
 # C preprocessor flags come before any C/CXX flags
 case "$mode" in
    cpp|as|cc|ccld)
-        extend flags_list SPACK_CPPFLAGS
-        ;;
+        flags=("${flags[@]}" "${SPACK_CPPFLAGS[@]}") ;;
 esac


@@ -609,67 +479,67 @@ case "$mode" in
    cc|ccld)
        case $lang_flags in
            C)
-                extend flags_list SPACK_CFLAGS
-                ;;
+                flags=("${flags[@]}" "${SPACK_CFLAGS[@]}") ;;
            CXX)
-                extend flags_list SPACK_CXXFLAGS
-                ;;
+                flags=("${flags[@]}" "${SPACK_CXXFLAGS[@]}") ;;
        esac
-
-        # prepend target args
-        preextend flags_list SPACK_TARGET_ARGS
+        flags=(${SPACK_TARGET_ARGS[@]} "${flags[@]}")
        ;;
 esac

 # Linker flags
 case "$mode" in
    ld|ccld)
-        extend flags_list SPACK_LDFLAGS
-        ;;
+        flags=("${flags[@]}" "${SPACK_LDFLAGS[@]}") ;;
 esac

 # On macOS insert headerpad_max_install_names linker flag
-if [ "$mode" = ld ] || [ "$mode" = ccld ]; then
-    if [ "${SPACK_SHORT_SPEC#*darwin}" != "${SPACK_SHORT_SPEC}" ]; then
-        case "$mode" in
-            ld)
-                append flags_list "-headerpad_max_install_names" ;;
-            ccld)
-                append flags_list "-Wl,-headerpad_max_install_names" ;;
-        esac
-    fi
+if [[ ($mode == ld || $mode == ccld) && "$SPACK_SHORT_SPEC" =~ "darwin" ]];
+then
+    case "$mode" in
+        ld)
+            flags=("${flags[@]}" -headerpad_max_install_names) ;;
+        ccld)
+            flags=("${flags[@]}" "-Wl,-headerpad_max_install_names") ;;
+    esac
 fi

-if [ "$mode" = ccld ] || [ "$mode" = ld ]; then
-    if [ "$add_rpaths" != "false" ]; then
+IFS=':' read -ra rpath_dirs <<< "$SPACK_RPATH_DIRS"
+if [[ $mode == ccld || $mode == ld ]]; then
+
+    if [[ "$add_rpaths" != "false" ]] ; then
        # Append RPATH directories. Note that in the case of the
        # top-level package these directories may not exist yet. For dependencies
        # it is assumed that paths have already been confirmed.
-        extend rpath_dirs_list SPACK_RPATH_DIRS
+        rpaths=("${rpaths[@]}" "${rpath_dirs[@]}")
    fi
+
 fi

-if [ "$mode" = ccld ] || [ "$mode" = ld ]; then
-    extend lib_dirs_list SPACK_LINK_DIRS
+IFS=':' read -ra link_dirs <<< "$SPACK_LINK_DIRS"
+if [[ $mode == ccld || $mode == ld ]]; then
+    libdirs=("${libdirs[@]}" "${link_dirs[@]}")
 fi

 # add RPATHs if we're in in any linking mode
 case "$mode" in
    ld|ccld)
        # Set extra RPATHs
-        extend lib_dirs_list SPACK_COMPILER_EXTRA_RPATHS
-        if [ "$add_rpaths" != "false" ]; then
-            extend rpath_dirs_list SPACK_COMPILER_EXTRA_RPATHS
+        IFS=':' read -ra extra_rpaths <<< "$SPACK_COMPILER_EXTRA_RPATHS"
+        libdirs+=("${extra_rpaths[@]}")
+        if [[ "$add_rpaths" != "false" ]] ; then
+            rpaths+=("${extra_rpaths[@]}")
        fi

        # Set implicit RPATHs
-        if [ "$add_rpaths" != "false" ]; then
-            extend rpath_dirs_list SPACK_COMPILER_IMPLICIT_RPATHS
+        IFS=':' read -ra implicit_rpaths <<< "$SPACK_COMPILER_IMPLICIT_RPATHS"
+        if [[ "$add_rpaths" != "false" ]] ; then
+            rpaths+=("${implicit_rpaths[@]}")
        fi

        # Add SPACK_LDLIBS to args
-        for lib in $SPACK_LDLIBS; do
-            append libs_list "${lib#-l}"
+        for lib in "${SPACK_LDLIBS[@]}"; do
+            libs+=("${lib#-l}")
        done
        ;;
 esac
@@ -677,62 +547,63 @@ esac
 #
 # Finally, reassemble the command line.
 #
-args_list="$flags_list"
+
+# Includes and system includes first
+args=()
+
+# flags assembled earlier
+args+=("${flags[@]}")

 # Insert include directories just prior to any system include directories
-# NOTE: adding ${lsep} to the prefix here turns every added element into two
-extend args_list include_dirs_list "-I"
-extend args_list isystem_include_dirs_list "-isystem${lsep}"

-case "$mode" in
-    cpp|cc|as|ccld)
-        if [ "$isystem_was_used" = "true" ]; then
-            extend args_list SPACK_INCLUDE_DIRS "-isystem${lsep}"
-        else
-            extend args_list SPACK_INCLUDE_DIRS "-I"
-        fi
-        ;;
-esac
+for dir in "${includes[@]}";         do args+=("-I$dir"); done
+for dir in "${isystem_includes[@]}";         do args+=("-isystem" "$dir"); done

-extend args_list system_include_dirs_list -I
-extend args_list isystem_system_include_dirs_list "-isystem${lsep}"
+IFS=':' read -ra spack_include_dirs <<< "$SPACK_INCLUDE_DIRS"
+if [[ $mode == cpp || $mode == cc || $mode == as || $mode == ccld ]]; then
+    if [[ "$isystem_was_used" == "true" ]] ; then
+        for dir in "${spack_include_dirs[@]}";  do args+=("-isystem" "$dir"); done
+    else
+        for dir in "${spack_include_dirs[@]}";  do args+=("-I$dir"); done
+    fi
+fi
+
+for dir in "${system_includes[@]}";  do args+=("-I$dir"); done
+for dir in "${isystem_system_includes[@]}";  do args+=("-isystem" "$dir"); done

 # Library search paths
-extend args_list lib_dirs_list "-L"
-extend args_list system_lib_dirs_list "-L"
+for dir in "${libdirs[@]}";          do args+=("-L$dir"); done
+for dir in "${system_libdirs[@]}";   do args+=("-L$dir"); done

 # RPATHs arguments
 case "$mode" in
    ccld)
-        if [ -n "$dtags_to_add" ] ; then
-            append args_list "$linker_arg$dtags_to_add"
-        fi
-        extend args_list rpath_dirs_list "$rpath"
-        extend args_list system_rpath_dirs_list "$rpath"
+        if [ -n "$dtags_to_add" ] ; then args+=("$linker_arg$dtags_to_add") ; fi
+        for dir in "${rpaths[@]}";        do args+=("$rpath$dir"); done
+        for dir in "${system_rpaths[@]}"; do args+=("$rpath$dir"); done
        ;;
    ld)
-        if [ -n "$dtags_to_add" ] ; then
-            append args_list "$dtags_to_add"
-        fi
-        extend args_list rpath_dirs_list "-rpath${lsep}"
-        extend args_list system_rpath_dirs_list "-rpath${lsep}"
+        if [ -n "$dtags_to_add" ] ; then args+=("$dtags_to_add") ; fi
+        for dir in "${rpaths[@]}";        do args+=("-rpath" "$dir"); done
+        for dir in "${system_rpaths[@]}"; do args+=("-rpath" "$dir"); done
        ;;
 esac

 # Other arguments from the input command
-extend args_list other_args_list
+args+=("${other_args[@]}")

 # Inject SPACK_LDLIBS, if supplied
-extend args_list libs_list "-l"
+for lib in "${libs[@]}"; do
+    args+=("-l$lib");
+done

-full_command_list="$command"
-extend full_command_list args_list
+full_command=("$command" "${args[@]}")

 # prepend the ccache binary if we're using ccache
 if [ -n "$SPACK_CCACHE_BINARY" ]; then
    case "$lang_flags" in
        C|CXX)  # ccache only supports C languages
-            prepend full_command_list "${SPACK_CCACHE_BINARY}"
+            full_command=("${SPACK_CCACHE_BINARY}" "${full_command[@]}")
            # workaround for stage being a temp folder
            # see #3761#issuecomment-294352232
            export CCACHE_NOHASHDIR=yes
@@ -741,36 +612,25 @@ if [ -n "$SPACK_CCACHE_BINARY" ]; then
 fi

 # dump the full command if the caller supplies SPACK_TEST_COMMAND=dump-args
-if [ -n "${SPACK_TEST_COMMAND=}" ]; then
-    case "$SPACK_TEST_COMMAND" in
-        dump-args)
-            IFS="$lsep"
-            for arg in $full_command_list; do
-                echo "$arg"
-            done
-            unset IFS
-            exit
-            ;;
-        dump-env-*)
-            var=${SPACK_TEST_COMMAND#dump-env-}
-            eval "printf '%s\n' \"\$0: \$var: \$$var\""
-            ;;
-        *)
-            die "Unknown test command: '$SPACK_TEST_COMMAND'"
-            ;;
-    esac
+if [[ $SPACK_TEST_COMMAND == dump-args ]]; then
+    IFS="
+" && echo "${full_command[*]}"
+    exit
+elif [[ $SPACK_TEST_COMMAND =~ dump-env-* ]]; then
+    var=${SPACK_TEST_COMMAND#dump-env-}
+    echo "$0: $var: ${!var}"
+elif [[ -n $SPACK_TEST_COMMAND ]]; then
+    die "ERROR: Unknown test command"
 fi

 #
 # Write the input and output commands to debug logs if it's asked for.
 #
-if [ "$SPACK_DEBUG" = TRUE ]; then
+if [[ $SPACK_DEBUG == TRUE ]]; then
    input_log="$SPACK_DEBUG_LOG_DIR/spack-cc-$SPACK_DEBUG_LOG_ID.in.log"
    output_log="$SPACK_DEBUG_LOG_DIR/spack-cc-$SPACK_DEBUG_LOG_ID.out.log"
    echo "[$mode] $command $input_command" >> "$input_log"
-    echo "[$mode] ${full_command_list}" >> "$output_log"
+    echo "[$mode] ${full_command[*]}" >> "$output_log"
 fi

-# Execute the full command, preserving spaces with IFS set
-# to the alarm bell separator.
-IFS="$lsep"; exec $full_command_list
+exec "${full_command[@]}"
--- a/lib/spack/env/oneapi/dpcpp
+++ b/lib/spack/env/oneapi/dpcpp
@@ -1 +0,0 @@
-../cc
--- a/lib/spack/external/init.py
+++ b/lib/spack/external/init.py
@@ -11,26 +11,19 @@

 * Homepage: https://pypi.python.org/pypi/archspec
 * Usage: Labeling, comparison and detection of microarchitectures
-* Version: 0.1.2 (commit 85757b6666422fca86aa882a769bf78b0f992f54)
+* Version: 0.1.2 (commit 4dbf253daf37e4a008e4beb6489f347b4a35aed4)

 argparse
 --------

 * Homepage: https://pypi.python.org/pypi/argparse
-* Usage: We include our own version to be Python 3.X compatible.
+* Usage: We include our own version to be Python 2.6 compatible.
 * Version: 1.4.0
 * Note: This package has been slightly modified to improve
  error message formatting. See the following commit if the
  vendored copy ever needs to be updated again:
  https://github.com/spack/spack/pull/6786/commits/dfcef577b77249106ea4e4c69a6cd9e64fa6c418

-attrs
----------------
-
-* Homepage: https://github.com/python-attrs/attrs
-* Usage: Needed by jsonschema.
-* Version: 21.2.0 (83d3cd70f90a3f4d19ee8b508e58d1c58821c0ad)
-
 ctest_log_parser
 ----------------

@@ -44,36 +37,49 @@

 * Homepage: https://pypi.python.org/pypi/distro
 * Usage: Provides a more stable linux distribution detection.
-* Version: 1.6.0 (64946a1e2a9ff529047070657728600e006c99ff)
-* Note: Last version supporting Python 2.7
+* Version: 1.0.4 (last version supporting Python 2.6)

-functools32
-----------
-* Homepage: https://github.com/MiCHiLU/python-functools32
-* Usage: Needed by jsonschema when using Python 2.7.
-* Version: 3.2.3-2
+functools
+---------
+
+* Homepage: https://github.com/python/cpython/blob/2.7/Lib/functools.py
+* Usage: Used for implementation of total_ordering.
+* Version: Unversioned
+* Note: This is the functools.total_ordering implementation
+  from Python 2.7 backported so we can run on Python 2.6.

 jinja2
 ------

 * Homepage: https://pypi.python.org/pypi/Jinja2
 * Usage: A modern and designer-friendly templating language for Python.
-* Version: 2.11.3 (last version supporting Python 2.7)
+* Version: 2.10

 jsonschema
 ----------

 * Homepage: https://pypi.python.org/pypi/jsonschema
 * Usage: An implementation of JSON Schema for Python.
-* Version: 3.2.0 (last version before 2.7 and 3.6 support was dropped)
-* Note: We don't include tests or benchmarks; just what Spack needs.
+* Version: 2.4.0 (last version before functools32 dependency was added)
+* Note: functools32 doesn't support Python 2.6 or 3.0, so jsonschema
+  cannot be upgraded any further until we drop 2.6.
+  Also, jsonschema/validators.py has been modified NOT to try to import
+  requests (see 7a1dd517b8).

 markupsafe
 ----------

 * Homepage: https://pypi.python.org/pypi/MarkupSafe
 * Usage: Implements a XML/HTML/XHTML Markup safe string for Python.
-* Version: 1.1.1 (last version supporting Python 2.7)
+* Version: 1.0
+
+orderddict
+----------
+
+* Homepage: https://pypi.org/project/ordereddict/
+* Usage: A drop-in substitute for Py2.7's new collections.OrderedDict
+  that works in Python 2.4-2.6.
+* Version: 1.1

 py
 --
@@ -82,16 +88,6 @@
 * Usage: Needed by pytest. Library with cross-python path,
  ini-parsing, io, code, and log facilities.
 * Version: 1.4.34 (last version supporting Python 2.6)
-* Note: This packages has been modified:
-  * https://github.com/pytest-dev/py/pull/186 was backported
-
-pyrsistent
----------
-
-* Homepage: http://github.com/tobgu/pyrsistent/
-* Usage: Needed by `jsonschema`
-* Version: 0.16.1 (last version supporting Python 2.7)
-* Note: We only include the parts needed for `jsonschema`.

 pytest
 ------
@@ -122,7 +118,7 @@

 * Homepage: https://pypi.python.org/pypi/six
 * Usage: Python 2 and 3 compatibility utilities.
-* Version: 1.16.0
+* Version: 1.11.0

 macholib
 --------
--- a/lib/spack/external/pytest-fallback/_pytest/LICENSE
+++ b/lib/spack/external/pytest-fallback/_pytest/LICENSE
--- a/lib/spack/external/pytest-fallback/_pytest/init.py
+++ b/lib/spack/external/pytest-fallback/_pytest/init.py
--- a/lib/spack/external/pytest-fallback/_pytest/_argcomplete.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_argcomplete.py
--- a/lib/spack/external/pytest-fallback/_pytest/_code/init.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_code/init.py
--- a/lib/spack/external/pytest-fallback/_pytest/_code/_py2traceback.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_code/_py2traceback.py
--- a/lib/spack/external/pytest-fallback/_pytest/_code/code.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_code/code.py
--- a/lib/spack/external/pytest-fallback/_pytest/_code/source.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_code/source.py
--- a/lib/spack/external/pytest-fallback/_pytest/_pluggy.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_pluggy.py
--- a/lib/spack/external/pytest-fallback/_pytest/_version.py
+++ b/lib/spack/external/pytest-fallback/_pytest/_version.py
--- a/lib/spack/external/pytest-fallback/_pytest/assertion/init.py
+++ b/lib/spack/external/pytest-fallback/_pytest/assertion/init.py
--- a/lib/spack/external/pytest-fallback/_pytest/assertion/rewrite.py
+++ b/lib/spack/external/pytest-fallback/_pytest/assertion/rewrite.py
--- a/lib/spack/external/pytest-fallback/_pytest/assertion/truncate.py
+++ b/lib/spack/external/pytest-fallback/_pytest/assertion/truncate.py
--- a/lib/spack/external/pytest-fallback/_pytest/assertion/util.py
+++ b/lib/spack/external/pytest-fallback/_pytest/assertion/util.py
--- a/lib/spack/external/pytest-fallback/_pytest/cacheprovider.py
+++ b/lib/spack/external/pytest-fallback/_pytest/cacheprovider.py
--- a/lib/spack/external/pytest-fallback/_pytest/capture.py
+++ b/lib/spack/external/pytest-fallback/_pytest/capture.py
--- a/lib/spack/external/pytest-fallback/_pytest/compat.py
+++ b/lib/spack/external/pytest-fallback/_pytest/compat.py
--- a/lib/spack/external/pytest-fallback/_pytest/config.py
+++ b/lib/spack/external/pytest-fallback/_pytest/config.py
--- a/lib/spack/external/pytest-fallback/_pytest/debugging.py
+++ b/lib/spack/external/pytest-fallback/_pytest/debugging.py
--- a/lib/spack/external/pytest-fallback/_pytest/deprecated.py
+++ b/lib/spack/external/pytest-fallback/_pytest/deprecated.py
--- a/lib/spack/external/pytest-fallback/_pytest/doctest.py
+++ b/lib/spack/external/pytest-fallback/_pytest/doctest.py
--- a/lib/spack/external/pytest-fallback/_pytest/fixtures.py
+++ b/lib/spack/external/pytest-fallback/_pytest/fixtures.py
@@ -1,6 +1,5 @@
 from __future__ import absolute_import, division, print_function

-import collections
 import inspect
 import sys
 import warnings
@@ -22,6 +21,9 @@
 from _pytest.outcomes import fail, TEST_OUTCOME


+from ordereddict_backport import OrderedDict
+
+
 def pytest_sessionstart(session):
    import _pytest.python
    scopename2class.update({
@@ -163,7 +165,7 @@ def reorder_items(items):
    for scopenum in range(0, scopenum_function):
        argkeys_cache[scopenum] = d = {}
        for item in items:
-            keys = collections.OrderedDict.fromkeys(get_parametrized_fixture_keys(item, scopenum))
+            keys = OrderedDict.fromkeys(get_parametrized_fixture_keys(item, scopenum))
            if keys:
                d[item] = keys
    return reorder_items_atscope(items, set(), argkeys_cache, 0)
@@ -198,7 +200,7 @@ def slice_items(items, ignore, scoped_argkeys_cache):
        for i, item in enumerate(it):
            argkeys = scoped_argkeys_cache.get(item)
            if argkeys is not None:
-                newargkeys = collections.OrderedDict.fromkeys(k for k in argkeys if k not in ignore)
+                newargkeys = OrderedDict.fromkeys(k for k in argkeys if k not in ignore)
                if newargkeys:  # found a slicing key
                    slicing_argkey, _ = newargkeys.popitem()
                    items_before = items[:i]
--- a/lib/spack/external/pytest-fallback/_pytest/freeze_support.py
+++ b/lib/spack/external/pytest-fallback/_pytest/freeze_support.py
--- a/lib/spack/external/pytest-fallback/_pytest/helpconfig.py
+++ b/lib/spack/external/pytest-fallback/_pytest/helpconfig.py
--- a/lib/spack/external/pytest-fallback/_pytest/hookspec.py
+++ b/lib/spack/external/pytest-fallback/_pytest/hookspec.py
--- a/lib/spack/external/pytest-fallback/_pytest/junitxml.py
+++ b/lib/spack/external/pytest-fallback/_pytest/junitxml.py
--- a/lib/spack/external/pytest-fallback/_pytest/main.py
+++ b/lib/spack/external/pytest-fallback/_pytest/main.py
--- a/lib/spack/external/pytest-fallback/_pytest/mark.py
+++ b/lib/spack/external/pytest-fallback/_pytest/mark.py
--- a/lib/spack/external/pytest-fallback/_pytest/monkeypatch.py
+++ b/lib/spack/external/pytest-fallback/_pytest/monkeypatch.py
--- a/lib/spack/external/pytest-fallback/_pytest/nodes.py
+++ b/lib/spack/external/pytest-fallback/_pytest/nodes.py
--- a/lib/spack/external/pytest-fallback/_pytest/nose.py
+++ b/lib/spack/external/pytest-fallback/_pytest/nose.py
--- a/lib/spack/external/pytest-fallback/_pytest/outcomes.py
+++ b/lib/spack/external/pytest-fallback/_pytest/outcomes.py
--- a/lib/spack/external/pytest-fallback/_pytest/pastebin.py
+++ b/lib/spack/external/pytest-fallback/_pytest/pastebin.py
--- a/lib/spack/external/pytest-fallback/_pytest/pytester.py
+++ b/lib/spack/external/pytest-fallback/_pytest/pytester.py
--- a/lib/spack/external/pytest-fallback/_pytest/python.py
+++ b/lib/spack/external/pytest-fallback/_pytest/python.py
--- a/lib/spack/external/pytest-fallback/_pytest/python_api.py
+++ b/lib/spack/external/pytest-fallback/_pytest/python_api.py
--- a/lib/spack/external/pytest-fallback/_pytest/recwarn.py
+++ b/lib/spack/external/pytest-fallback/_pytest/recwarn.py
--- a/lib/spack/external/pytest-fallback/_pytest/resultlog.py
+++ b/lib/spack/external/pytest-fallback/_pytest/resultlog.py
--- a/lib/spack/external/pytest-fallback/_pytest/runner.py
+++ b/lib/spack/external/pytest-fallback/_pytest/runner.py
--- a/lib/spack/external/pytest-fallback/_pytest/setuponly.py
+++ b/lib/spack/external/pytest-fallback/_pytest/setuponly.py
--- a/lib/spack/external/pytest-fallback/_pytest/setupplan.py
+++ b/lib/spack/external/pytest-fallback/_pytest/setupplan.py
--- a/lib/spack/external/pytest-fallback/_pytest/skipping.py
+++ b/lib/spack/external/pytest-fallback/_pytest/skipping.py
--- a/lib/spack/external/pytest-fallback/_pytest/terminal.py
+++ b/lib/spack/external/pytest-fallback/_pytest/terminal.py
--- a/lib/spack/external/pytest-fallback/_pytest/tmpdir.py
+++ b/lib/spack/external/pytest-fallback/_pytest/tmpdir.py
--- a/lib/spack/external/pytest-fallback/_pytest/unittest.py
+++ b/lib/spack/external/pytest-fallback/_pytest/unittest.py
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/README.md
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/README.md
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/init.py
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/init.py
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/DESCRIPTION.rst
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/DESCRIPTION.rst
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/INSTALLER
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/INSTALLER
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/LICENSE.txt
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/LICENSE.txt
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/METADATA
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/METADATA
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/RECORD
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/RECORD
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/WHEEL
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/WHEEL
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/metadata.json
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/metadata.json
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/top_level.txt
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy-0.4.0.dist-info/top_level.txt
--- a/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy.py
+++ b/lib/spack/external/pytest-fallback/_pytest/vendored_packages/pluggy.py
--- a/lib/spack/external/pytest-fallback/_pytest/warnings.py
+++ b/lib/spack/external/pytest-fallback/_pytest/warnings.py
--- a/lib/spack/external/archspec/README.md
+++ b/lib/spack/external/archspec/README.md
@@ -49,19 +49,6 @@ $ tox
  congratulations :)
 ```

-## Citing Archspec
-
-If you are referencing `archspec` in a publication, please cite the following
-paper:
-
- * Massimiliano Culpo, Gregory Becker, Carlos Eduardo Arango Gutierrez, Kenneth
-   Hoste, and Todd Gamblin.
-   [**`archspec`: A library for detecting, labeling, and reasoning about
-   microarchitectures**](https://tgamblin.github.io/pubs/archspec-canopie-hpc-2020.pdf).
-   In *2nd International Workshop on Containers and New Orchestration Paradigms
-   for Isolated Environments in HPC (CANOPIE-HPC'20)*, Online Event, November
-   12, 2020.
-
 ## License

 Archspec is distributed under the terms of both the MIT license and the
--- a/lib/spack/external/archspec/cpu/detect.py
+++ b/lib/spack/external/archspec/cpu/detect.py
@@ -206,26 +206,11 @@ def host():
    # Get a list of possible candidates for this micro-architecture
    candidates = compatible_microarchitectures(info)

-    # Sorting criteria for candidates
-    def sorting_fn(item):
-        return len(item.ancestors), len(item.features)
-
-    # Get the best generic micro-architecture
-    generic_candidates = [c for c in candidates if c.vendor == "generic"]
-    best_generic = max(generic_candidates, key=sorting_fn)
-
-    # Filter the candidates to be descendant of the best generic candidate.
-    # This is to avoid that the lack of a niche feature that can be disabled
-    # from e.g. BIOS prevents detection of a reasonably performant architecture
-    candidates = [c for c in candidates if c > best_generic]
-
-    # If we don't have candidates, return the best generic micro-architecture
-    if not candidates:
-        return best_generic
-
    # Reverse sort of the depth for the inheritance tree among only targets we
    # can use. This gets the newest target we satisfy.
-    return max(candidates, key=sorting_fn)
+    return sorted(
+        candidates, key=lambda t: (len(t.ancestors), len(t.features)), reverse=True
+    )[0]


 def compatibility_check(architecture_family):
@@ -260,13 +245,7 @@ def compatibility_check_for_power(info, target):
    """Compatibility check for PPC64 and PPC64LE architectures."""
    basename = platform.machine()
    generation_match = re.search(r"POWER(\d+)", info.get("cpu", ""))
-    try:
-        generation = int(generation_match.group(1))
-    except AttributeError:
-        # There might be no match under emulated environments. For instance
-        # emulating a ppc64le with QEMU and Docker still reports the host
-        # /proc/cpuinfo and not a Power
-        generation = 0
+    generation = int(generation_match.group(1))

    # We can use a target if it descends from our machine type and our
    # generation (9 for POWER9, etc) is at least its generation.
@@ -306,22 +285,3 @@ def compatibility_check_for_aarch64(info, target):
        and (target.vendor == vendor or target.vendor == "generic")
        and target.features.issubset(features)
    )
-
-
-@compatibility_check(architecture_family="riscv64")
-def compatibility_check_for_riscv64(info, target):
-    """Compatibility check for riscv64 architectures."""
-    basename = "riscv64"
-    uarch = info.get("uarch")
-
-    # sifive unmatched board
-    if uarch == "sifive,u74-mc":
-        uarch = "u74mc"
-    # catch-all for unknown uarchs
-    else:
-        uarch = "riscv64"
-
-    arch_root = TARGETS[basename]
-    return (target == arch_root or arch_root in target.ancestors) and (
-        target == uarch or target.vendor == "generic"
-    )
--- a/lib/spack/external/archspec/cpu/microarchitecture.py
+++ b/lib/spack/external/archspec/cpu/microarchitecture.py
@@ -173,12 +173,6 @@ def family(self):

        return roots.pop()

-    @property
-    def generic(self):
-        """Returns the best generic architecture that is compatible with self"""
-        generics = [x for x in [self] + self.ancestors if x.vendor == "generic"]
-        return max(generics, key=lambda x: len(x.ancestors))
-
    def to_dict(self, return_list_of_items=False):
        """Returns a dictionary representation of this object.

--- a/lib/spack/external/archspec/json/cpu/microarchitectures.json
+++ b/lib/spack/external/archspec/json/cpu/microarchitectures.json
@@ -2017,44 +2017,6 @@
      "features": [],
      "compilers": {
      }
-    },
-    "riscv64": {
-      "from": [],
-      "vendor": "generic",
-      "features": [],
-      "compilers": {
-        "gcc": [
-          {
-            "versions": "7.1:",
-            "flags" : "-march=rv64gc"
-          }
-        ],
-        "clang": [
-          {
-            "versions": "9.0:",
-            "flags" : "-march=rv64gc"
-          }
-        ]
-      }
-    },
-    "u74mc": {
-      "from": ["riscv64"],
-      "vendor": "SiFive",
-      "features": [],
-      "compilers": {
-        "gcc": [
-          {
-            "versions": "10.2:",
-            "flags" : "-march=rv64gc -mtune=sifive-7-series"
-          }
-        ],
-        "clang" : [
-          {
-            "versions": "12.0:",
-            "flags" : "-march=rv64gc -mtune=sifive-7-series"
-          }
-        ]
-      }
    }
  },
  "feature_aliases": {
--- a/lib/spack/external/attr/LICENSE
+++ b/lib/spack/external/attr/LICENSE
@@ -1,21 +0,0 @@
-The MIT License (MIT)
-
-Copyright (c) 2015 Hynek Schlawack
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.
--- a/lib/spack/external/attr/init.py
+++ b/lib/spack/external/attr/init.py
@@ -1,78 +0,0 @@
-from __future__ import absolute_import, division, print_function
-
-import sys
-
-from functools import partial
-
-from . import converters, exceptions, filters, setters, validators
-from ._cmp import cmp_using
-from ._config import get_run_validators, set_run_validators
-from ._funcs import asdict, assoc, astuple, evolve, has, resolve_types
-from ._make import (
-    NOTHING,
-    Attribute,
-    Factory,
-    attrib,
-    attrs,
-    fields,
-    fields_dict,
-    make_class,
-    validate,
-)
-from ._version_info import VersionInfo
-
-
-__version__ = "21.2.0"
-__version_info__ = VersionInfo._from_version_string(__version__)
-
-__title__ = "attrs"
-__description__ = "Classes Without Boilerplate"
-__url__ = "https://www.attrs.org/"
-__uri__ = __url__
-__doc__ = __description__ + " <" + __uri__ + ">"
-
-__author__ = "Hynek Schlawack"
-__email__ = "hs@ox.cx"
-
-__license__ = "MIT"
-__copyright__ = "Copyright (c) 2015 Hynek Schlawack"
-
-
-s = attributes = attrs
-ib = attr = attrib
-dataclass = partial(attrs, auto_attribs=True)  # happy Easter ;)
-
-__all__ = [
-    "Attribute",
-    "Factory",
-    "NOTHING",
-    "asdict",
-    "assoc",
-    "astuple",
-    "attr",
-    "attrib",
-    "attributes",
-    "attrs",
-    "cmp_using",
-    "converters",
-    "evolve",
-    "exceptions",
-    "fields",
-    "fields_dict",
-    "filters",
-    "get_run_validators",
-    "has",
-    "ib",
-    "make_class",
-    "resolve_types",
-    "s",
-    "set_run_validators",
-    "setters",
-    "validate",
-    "validators",
-]
-
-if sys.version_info[:2] >= (3, 6):
-    from ._next_gen import define, field, frozen, mutable
-
-    __all__.extend((define, field, frozen, mutable))
--- a/Show More
+++ b/Show More