Move troublesome default -Werror from CMake to CI

Signed-off-by: Sebastian Pipping <sebastian@pipping.org>

Author: hartwork

.github/workflows/cmake-multi-platform.yml

@@ -52,7 +52,9 @@ jobs:
       run: >
         cmake -B ${{ steps.strings.outputs.build-output-dir }}
         -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
+        -DCMAKE_CXX_FLAGS='-Werror'
         -DCMAKE_C_COMPILER=${{ matrix.c_compiler }}
+        -DCMAKE_C_FLAGS='-Werror'
         -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
         -DLIB_PROTO_MUTATOR_DOWNLOAD_PROTOBUF=ON
         -GNinja

CMakeLists.txt

@@ -80,7 +80,7 @@ unset(CMAKE_REQUIRED_FLAGS)
 check_cxx_compiler_flag(-Wstring-conversion LIB_PROTO_MUTATOR_HAS_WSTRING_CONVERSION)
 
 if (NOT MSVC)
-  set(EXTRA_FLAGS "-fno-exceptions -Werror -Wall")
+  set(EXTRA_FLAGS "-fno-exceptions -Wall")
   if (LIB_PROTO_MUTATOR_HAS_WSTRING_CONVERSION)
     set(EXTRA_FLAGS "${EXTRA_FLAGS} -Wstring-conversion")
   endif()