Use "fetch-depth: 0" to retrieve all history from remote

.github/workflows/linux_unit_tests.yaml

@@ -19,6 +19,8 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
     - uses: actions/setup-python@v2
       with:
         python-version: ${{ matrix.python-version }}
@@ -35,9 +37,7 @@ jobs:
       run: |
           # Need this for the git tests to succeed.
           git --version
-          git config --global user.email "spack@example.com"
-          git config --global user.name "Test User"
-          git fetch -u origin develop:develop
+          . .github/workflows/setup_git.sh
     - name: Install kcov for bash script coverage
       env:
           KCOV_VERSION: 34
@@ -62,6 +62,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
     - uses: actions/setup-python@v2
       with:
         python-version: 3.8
@@ -78,9 +80,7 @@ jobs:
       run: |
           # Need this for the git tests to succeed.
           git --version
-          git config --global user.email "spack@example.com"
-          git config --global user.name "Test User"
-          git fetch -u origin develop:develop
+          . .github/workflows/setup_git.sh
     - name: Install kcov for bash script coverage
       env:
           KCOV_VERSION: 38

.github/workflows/macos_unit_tests.yaml

@@ -14,6 +14,8 @@ jobs:
     runs-on: macos-latest
     steps:
     - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
     - uses: actions/setup-python@v2
       with:
         python-version: 3.7
@@ -30,7 +32,7 @@ jobs:
     - name: Run unit tests
       run: |
         git --version
-        git fetch -u origin develop:develop
+        . .github/workflows/setup_git.sh
         . share/spack/setup-env.sh
         coverage run $(which spack) test
         coverage combine

.github/workflows/setup_git.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env sh
+git config --global user.email "spack@example.com"
+git config --global user.name "Test User"
+# 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

.github/workflows/style_and_docs.yaml

@@ -41,9 +41,7 @@ jobs:
       run: |
         # Need this for the git tests to succeed.
         git --version
-        git config --global user.email "spack@example.com"
-        git config --global user.name "Test User"
-        git fetch -u origin develop:develop
+        . .github/workflows/setup_git.sh
     - name: Run flake8 tests
       run: |
           share/spack/qa/run-flake8-tests