wip: build with gcc and clang

.github/workflows/linux-build.yml

@@ -1,4 +1,4 @@
-name: run all
+name: Linux build
 
 on:
   pull_request:
@@ -10,6 +10,11 @@ on:
 
 jobs:
   build:
+    strategy:
+      matrix:
+        compiler:
+          - g++
+          - clang++
     runs-on: ubuntu-22.04
 
     steps:
@@ -50,14 +55,16 @@ jobs:
       run: |
         cmake -E make_directory build
         cmake -E chdir build cmake \
+          -DCMAKE_CXX_COMPILER=${{ matrix.compiler }} \
+          -DCMAKE_C_COMPILER=${{ matrix.compiler }} \
           -G Ninja \
           -DCUKE_ENABLE_BOOST_TEST=on \
           -DCUKE_ENABLE_GTEST=on \
           -DCUKE_ENABLE_QT=on \
           -DCUKE_ENABLE_EXAMPLES=on \
           -DCUKE_TESTS_UNIT=on \
           ..
-        cmake --build build --parallel
+        cmake --build build --parallel --verbose
 
     - name: unit tests
       run: |