Add more diagnostics when configuring

Author: zpostfacto

.github/workflows/build.yml

@@ -72,9 +72,18 @@ jobs:
       - name: Install dependencies and generate project files
         run: |
           call %GITHUB_WORKSPACE%\.github\setup-msvc-env.bat
+          echo ==== Compiler diagnostics before configure ====
+          where cl || echo cl not found on PATH
+          where cc || echo cc not found on PATH
+          where c++.exe || echo c++.exe not found on PATH
+          echo CC=%CC%
+          echo CXX=%CXX%
           mkdir build
           cd build
           cmake -S .. -G Ninja -DCMAKE_C_COMPILER=cl -DCMAKE_CXX_COMPILER=cl -DBUILD_TESTS=ON -DBUILD_EXAMPLES=ON -DBUILD_TOOLS=ON -DCMAKE_TOOLCHAIN_FILE=${{env.VCPKG_ROOT}}/scripts/buildsystems/vcpkg.cmake -DUSE_CRYPTO=${{matrix.crypto}}
+          echo ==== CMake compiler cache ====
+          findstr /R "^CMAKE_C_COMPILER:.*" CMakeCache.txt
+          findstr /R "^CMAKE_CXX_COMPILER:.*" CMakeCache.txt
         shell: cmd
 
       - name: Build projects