warnings treated as errors; added debug CI build

.gitlab-ci.yml

@@ -32,6 +32,10 @@ build:update_dune:
     - ARGS="--output-on-failure -j 2" ./dune-common/bin/dunecontrol --only=dorie make test
   stage: build
 
+build:debug:
+  script:
+    - CMAKE_FLAGS="-DCMAKE_BUILD_TYPE=Debug" ./dune-common/bin/dunecontrol --only=dorie all
+
 deploy:docs:
   script:
     - cd $CI_PROJECT_DIR && bash .deploy_docs

CMakeLists.txt

@@ -10,7 +10,7 @@ string(TOUPPER ${CMAKE_BUILD_TYPE} CMAKE_BUILD_TYPE_UPPER)
 if(CMAKE_BUILD_TYPE_UPPER MATCHES DEBUG)
 	set(CMAKE_VERBOSE_MAKEFILE ON)
 endif()
-set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall")
+set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall -Werror")
 
 # 
 if(NOT (dune-common_DIR OR dune-common_ROOT OR