More legible build matrix elements in non-Conan CI

.github/workflows/ci-cmake.yml

@@ -1,4 +1,4 @@
-name: libcosim CI CMake
+name: libcosim CI without Conan
 
 # This workflow is triggered on pushes to the repository.
 on: [push]
@@ -10,8 +10,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        build_type: [Debug, Release]
-        shared_libs: [ON, OFF]
+        # Note: The all-caps prefixes are part of CMake variable names, and
+        # therefore must be written exactly as they are. They're included here
+        # to make the build matrix easier to understand when viewed in the
+        # GitHub web interface.
+        build_type: [BUILD_TYPE=Debug, BUILD_TYPE=Release]
+        shared_libs: [SHARED_LIBS=ON, SHARED_LIBS=OFF]
     timeout-minutes: 35
 
     steps:
@@ -45,7 +49,7 @@ jobs:
           #!/bin/bash
           mkdir build
           cd build
-          cmake -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DBUILD_SHARED_LIBS=${{ matrix.shared_libs }} /mnt/source
+          cmake -DCMAKE_${{ matrix.build_type }} -DBUILD_${{ matrix.shared_libs }} /mnt/source
           cmake --build .
           ctest --output-on-failure
           EOF