fix problems after merge

.gitlab-ci.yml

@@ -16,7 +16,7 @@ dune-2.7:
   - dunecontrol --current make -j2 examples
 
 dune-git-clang:
-  image: registry.dune-project.org/docker/ci/dune:git-ubuntu-18.04-clang-6-17
+  image: registry.dune-project.org/docker/ci/dune:git-debian-10-clang-7-libcpp-17
   script:
   - duneci-standard-test
   - dunecontrol --current make -j2 examples