Only checkout the target branch

.github/workflows/analysis.yml

@@ -7,6 +7,8 @@ jobs:
     runs-on: ubuntu-18.04
     steps:
       - uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
       - run:  sudo apt-get update
       - name: Install pylint
         run:  |
@@ -23,6 +25,8 @@ jobs:
     needs: run_linters
     steps:
       - uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
       - run:  sudo apt-get update
       - name: Install C++ compiler and libraries
         run:  sudo apt-get install python3-setuptools $(./scripts/list-build-dependencies.sh -m apt -c gcc)
@@ -63,6 +67,8 @@ jobs:
         compiler: [Clang, GCC]
     steps:
       - uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
       - run:  sudo apt-get update
       - name: Install C++ compiler and libraries
         env:

.github/workflows/linux.yml

@@ -27,6 +27,8 @@ jobs:
             max_warnings: 150
     steps:
       - uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
       - run:  sudo apt-get update
       - name: Install C++ compiler and libraries
         run:  sudo apt-get install -y $(./scripts/list-build-dependencies.sh -m apt ${{ matrix.conf.flags }})
@@ -44,6 +46,8 @@ jobs:
     runs-on: ubuntu-16.04
     steps:
       - uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
       - run:  sudo apt-get update
       - name: Install C++ compiler and libraries
         run:  sudo apt-get install -y tree $(./scripts/list-build-dependencies.sh -m apt -c gcc)

.github/workflows/macos.yml

@@ -17,6 +17,8 @@ jobs:
             max_warnings: 277
     steps:
       - uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
       - name: Install C++ compiler and libraries
         run:  brew install $(./scripts/list-build-dependencies.sh -m brew ${{ matrix.conf.flags}})
       - name: Log environment

.github/workflows/windows.yml

@@ -29,6 +29,8 @@ jobs:
       CHERE_INVOKING: yes
     steps:
       - uses:  actions/checkout@v1
+        with:
+          fetch-depth: 1
       - name:  Get Date
         id:    get-date
         shell: bash
@@ -75,6 +77,8 @@ jobs:
         type: [Debug]
     steps:
       - uses:  actions/checkout@v1
+        with:
+          fetch-depth: 1
       - name:  Install packages
         shell: pwsh
         run: |
@@ -96,6 +100,8 @@ jobs:
     runs-on: windows-latest
     steps:
       - uses:  actions/checkout@v1
+        with:
+          fetch-depth: 1
       - name:  Install packages
         shell: pwsh
         run: |