Use Ubuntu 20.04 for coverage

Author: 2-towns

.github/actions/nimbus-build-system/action.yml

@@ -85,8 +85,8 @@ runs:
         pacman -U --noconfirm https://repo.msys2.org/mingw/ucrt64/mingw-w64-ucrt-x86_64-gcc-14.2.0-2-any.pkg.tar.zst https://repo.msys2.org/mingw/ucrt64/mingw-w64-ucrt-x86_64-gcc-libs-14.2.0-2-any.pkg.tar.zst
 
     - name: Install gcc 14 on Linux
-      # Should be removed when ubuntu-latest is 26.04
-      if : ${{ inputs.os == 'linux' }}
+      # We don't want to install gcc 14 for coverage (Ubuntu 20.04)
+      if : ${{ inputs.os == 'linux' && !inputs.coverage }}
       shell: ${{ inputs.shell }} {0}
       run: |
         # Add GCC-14 to alternatives

.github/workflows/ci-reusable.yml

@@ -40,6 +40,7 @@ jobs:
           os: ${{ matrix.os }}
           shell: ${{ matrix.shell }}
           nim_version: ${{ matrix.nim_version }}
+          coverage: false
 
       ## Part 1 Tests ##
       - name: Unit tests

.github/workflows/ci.yml

@@ -48,7 +48,11 @@ jobs:
       cache_nonce: ${{ needs.matrix.outputs.cache_nonce }}
 
   coverage:
-    runs-on: ubuntu-latest
+    # Force to stick to ubuntu 20.04 for coverage because
+    # lcov was updated to 2.x version in ubuntu-latest
+    # and cause a lot of issues.
+    # See https://github.com/linux-test-project/lcov/issues/238
+    runs-on: ubuntu-20.04
     steps:
       - name: Checkout sources
         uses: actions/checkout@v4
@@ -61,6 +65,7 @@ jobs:
         with:
           os: linux
           nim_version: ${{ env.nim_version }}
+          coverage: true
 
       - name: Generate coverage data
         run: |