github actions CI: win/mac both need linux succeed first, fixes #7684

also:
- XDISTN=6, 3 cores on macOS machines
- XDISTN=4, 2 cores on windows/linux machines

.github/workflows/ci.yml

@@ -45,7 +45,7 @@ jobs:
         pip install flake8
         flake8 src scripts conftest.py
 
-  tox:
+  linux:
 
     needs: lint
     strategy:
@@ -64,6 +64,70 @@ jobs:
             - os: ubuntu-20.04
               python-version: '3.11'
               toxenv: py311-fuse3
+
+    env:
+      TOXENV: ${{ matrix.toxenv }}
+
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 60
+
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        # just fetching 1 commit is not enough for setuptools-scm, so we fetch all
+        fetch-depth: 0
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v4
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Cache pip
+      uses: actions/cache@v3
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('requirements.d/development.txt') }}
+        restore-keys: |
+            ${{ runner.os }}-pip-
+            ${{ runner.os }}-
+
+    - name: Install Linux packages
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y pkg-config build-essential
+        sudo apt-get install -y libssl-dev libacl1-dev libxxhash-dev liblz4-dev libzstd-dev
+        sudo apt-get install -y libfuse-dev fuse || true  # Required for Python llfuse module
+        sudo apt-get install -y libfuse3-dev fuse3 || true  # Required for Python pyfuse3 module
+
+    - name: Install Python requirements
+      run: |
+        python -m pip install --upgrade pip setuptools wheel
+        pip install -r requirements.d/development.txt
+    - name: Install borgbackup
+      run: |
+        # pip install -e .
+        python setup.py -v develop
+    - name: run tox env
+      env:
+        XDISTN: "4"
+      run: |
+        # do not use fakeroot, but run as root. avoids the dreaded EISDIR sporadic failures. see #2482.
+        #sudo -E bash -c "tox -e py"
+        tox --skip-missing-interpreters
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v3
+      env:
+        OS: ${{ runner.os }}
+        python: ${{ matrix.python-version }}
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}
+        env_vars: OS, python
+
+  macOS:
+
+    needs: linux
+    strategy:
+      fail-fast: true
+      matrix:
+        include:
             - os: macos-12
               python-version: '3.11'
               toxenv: py311-none  # note: no fuse testing, due to #6099, see also #6196.
@@ -94,17 +158,7 @@ jobs:
             ${{ runner.os }}-pip-
             ${{ runner.os }}-
 
-    - name: Install Linux packages
-      if: ${{ runner.os == 'Linux' }}
-      run: |
-        sudo apt-get update
-        sudo apt-get install -y pkg-config build-essential
-        sudo apt-get install -y libssl-dev libacl1-dev libxxhash-dev liblz4-dev libzstd-dev
-        sudo apt-get install -y libfuse-dev fuse || true  # Required for Python llfuse module
-        sudo apt-get install -y libfuse3-dev fuse3 || true  # Required for Python pyfuse3 module
-
     - name: Install macOS packages
-      if: ${{ runner.os == 'macOS' }}
       run: |
         brew install pkg-config || brew upgrade pkg-config
         brew install zstd || brew upgrade zstd
@@ -129,7 +183,7 @@ jobs:
         # we already have that in the global env, but something is broken and overwrites that.
         # so, set it here, again.
         PKG_CONFIG_PATH: "/usr/local/opt/openssl@1.1/lib/pkgconfig:$PKG_CONFIG_PATH"
-        XDISTN: "4"
+        XDISTN: "6"
       run: |
         # do not use fakeroot, but run as root. avoids the dreaded EISDIR sporadic failures. see #2482.
         #sudo -E bash -c "tox -e py"
@@ -147,7 +201,7 @@ jobs:
 
     runs-on: windows-latest
     timeout-minutes: 60
-    needs: lint
+    needs: linux
 
     env:
       SETUPTOOLS_USE_DISTUTILS: stdlib # Needed for pip to work - https://www.msys2.org/docs/python/#known-issues