fix missing .git directory

c.f actions/checkout#335 (comment)

.github/workflows/ci.yml

@@ -30,8 +30,26 @@ jobs:
           - TEST : debian-unstable
             DOCKER_IMAGE : debian:unstable
     steps:
+      - name: Setup OS
+        run: |
+          sudo apt-get update -y
+          sudo apt-get upgrade -y
+      - name: Setup Git
+        run: |
+          sudo apt-get install -y git
       - name: Chcekout
         uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+          submodules: recursive
+      - name: work around permission issue  # https://github.com/actions/checkout/issues/760#issuecomment-1097501613
+        run: |
+          set -x
+          export USER=$(whoami)
+          git config --global --add safe.directory $GITHUB_WORKSPACE || echo "OK" # Show 'could not lock config file /github/home/.gitconfig: Permission denied', but it is ok
+          sudo mkdir -p /__w/
+          sudo chmod 777 -R /__w/
+          sudo chown -R $USER $HOME
       # python3_check
       - name: python3_check
         if: matrix.CHECK_PYTHON3_COMPILE  == true

.travis.sh

@@ -163,6 +163,7 @@ elif [ "$TEST" == "clang-tidy" ]; then
 	    run-clang-tidy -fix -p $(dirname $file)
     done
     travis_time_end
+    sudo chown -R $USER $CI_SOURCE_PATH
     git -C $CI_SOURCE_PATH --no-pager diff
     git -C $CI_SOURCE_PATH diff-index --quiet HEAD -- .