Introduce a workaround for libstdc++ problem in CI

Author: SavchenkoValeriy

.github/workflows/test.yml

@@ -44,43 +44,62 @@ jobs:
     steps:
       - run: echo $LD_LIBRARY_PATH
       - run: find /usr/lib -name libstdc++.so.6
+
       - name: Checkout source code
         uses: actions/checkout@v2
+
       - name: Setup Swift
         if: runner.os == 'Linux'
         uses: swift-actions/setup-swift@v1
+
       - name: Setup Emacs
         uses: purcell/setup-emacs@master
         with:
           version: ${{ matrix.emacs-version }}
+
       - uses: actions/cache@v3
         id: cache-cask-packages
         with:
           path: .cask
           key: cache-cask-packages-000
+
       - uses: actions/cache@v3
         id: cache-cask-executable
         with:
           path: ~/.cask
           key: cache-cask-executable-000
+
       - name: Setup Cask
         uses: cask/setup-cask@master
         if: steps.cache-cask-executable.outputs.cache-hit != 'true'
         with:
           version: snapshot
+
       - run: echo "$HOME/.cask/bin" >> $GITHUB_PATH
+
       - name: Build the test module
         run: swift build -c ${{ matrix.configuration }}
+
       - name: Rename .dylib for older Emacs versions
         run: cp $BUILD_DIR/libTestModule.dylib $BUILD_DIR/$TEST_LIB
         if: matrix.emacs-version != 28.1 && runner.os == 'macOS'
+
       - name: Cask install test dependencies
         run: cask install
+
       # Enable tmate debugging of manually-triggered workflows if the input option was provided
       - name: Setup tmate session
         uses: mxschmitt/action-tmate@v3
         if: ${{ github.event_name == 'workflow_dispatch' && inputs.debug_enabled }}
+
+      # A nasty workaround for Swift standard libraries on linux that don't set their RPATH to
+      # libstdc++ properly. Evidently, it becomes problematic with nix installed Emacs.
+      - name: Create symlink and set LD_LIBRARY_PATH
+        run: |
+          mkdir -p /tmp/libstdc++
+          ln -s /usr/lib/x86_64-linux-gnu/libstdc++.so.6 /tmp/libstdc++/libstdc++.so.6
+
       - name: Run tests
         run: cask exec ert-runner -l $BUILD_DIR/$TEST_LIB -t emacs-${EMACS_VERSION%.*},emacs-all
         env:
-          LD_LIBRARY_PATH: /usr/lib/x86_64-linux-gnu
+          LD_LIBRARY_PATH: /tmp/libstdc++