Add testing for Python 3.9 (#19261)

.github/workflows/linux_build_tests.yaml

@@ -45,7 +45,7 @@ jobs:
           ccache-build-${{ matrix.package }}
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install System Packages
       run: |
         sudo apt-get update

.github/workflows/linux_unit_tests.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [2.7, 3.5, 3.6, 3.7, 3.8]
+        python-version: [2.7, 3.5, 3.6, 3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2
@@ -65,7 +65,7 @@ jobs:
         fetch-depth: 0
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install System packages
       run: |
           sudo apt-get -y update

.github/workflows/macos_python.yml

@@ -27,7 +27,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh
@@ -42,7 +42,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh
@@ -55,7 +55,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh
@@ -70,7 +70,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: spack install
       run: |
         . .github/workflows/install_spack.sh

.github/workflows/macos_unit_tests.yaml

@@ -18,7 +18,7 @@ jobs:
         fetch-depth: 0
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install Python packages
       run: |
           pip install --upgrade pip six setuptools

.github/workflows/style_and_docs.yaml

@@ -16,7 +16,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install Python Packages
       run: |
         pip install --upgrade pip
@@ -33,7 +33,7 @@ jobs:
         fetch-depth: 0
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install Python packages
       run: |
         pip install --upgrade pip six setuptools flake8
@@ -51,7 +51,7 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: 3.9
     - name: Install System packages
       run: |
         sudo apt-get -y update

lib/spack/docs/getting_started.rst

@@ -16,7 +16,7 @@ Prerequisites
 Spack has the following minimum requirements, which must be installed
 before Spack is run:
 
-#. Python 2 (2.6 or 2.7) or 3 (3.5 - 3.8) to run Spack
+#. Python 2 (2.6 or 2.7) or 3 (3.5 - 3.9) to run Spack
 #. A C/C++ compiler for building
 #. The ``make`` executable for building
 #. The ``tar``, ``gzip``, ``bzip2``, ``xz`` and optionally ``zstd``
@@ -26,8 +26,8 @@ before Spack is run:
 #. If using the ``gpg`` subcommand, ``gnupg2`` is required
 
 These requirements can be easily installed on most modern Linux systems;
-on Macintosh, XCode is required.  Spack is designed to run on HPC
-platforms like Cray and BlueGene/Q.  Not all packages should be expected
+on macOS, XCode is required.  Spack is designed to run on HPC
+platforms like Cray.  Not all packages should be expected
 to work on all platforms.  A build matrix showing which packages are
 working on which systems is planned but not yet available.