test glibcxx-debug only on CPU

.gitlab-ci.yml

@@ -435,20 +435,6 @@ build/amd/nompi/clang/rocm45/debug/shared:
     RUN_EXAMPLES: "ON"
     BUILD_TYPE: "Debug"
 
-build/amd/nompi/clang/rocm45/glibcxx-debug/shared:
-  extends:
-    - .build_and_test_template
-    - .default_variables
-    - .quick_test_condition
-    - .use_gko-rocm45-nompi-gnu8-llvm8
-  variables:
-    C_COMPILER: "clang"
-    CXX_COMPILER: "clang++"
-    BUILD_OMP: "ON"
-    BUILD_HIP : "ON"
-    CXX_FLAGS: "-Wpedantic -D_GLIBCXX_DEBUG=1"
-    BUILD_TYPE: "Debug"
-
 # ROCm 5.0.2 and friends
 build/amd/nompi/gcc/rocm502/debug/static:
   extends:
@@ -538,6 +524,21 @@ build/nocuda/openmpi/clang/omp/debug/static:
     FAST_TESTS: "ON"
     BUILD_SHARED_LIBS: "OFF"
 
+build/nocuda/openmpi/clang/omp/glibcxx-debug/shared:
+  extends:
+    - .build_and_test_template
+    - .default_variables
+    - .quick_test_condition
+    - .use_gko-nocuda-nompi-gnu9-llvm8
+  variables:
+    CXX_COMPILER: "clang++"
+    BUILD_OMP: "ON"
+    MPI_AS_ROOT: "ON"
+    BUILD_MPI: "ON"
+    CXX_FLAGS: "-Wpedantic -D_GLIBCXX_DEBUG=1"
+    FAST_TESTS: "ON"
+    BUILD_TYPE: "Debug"
+
 # nocuda with the oldest supported compiler
 build/nocuda/nompi/gcc/omp/release/static:
   extends: