diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 93cf6b58..83cfeca0 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,6 +7,17 @@ on:
     branches: [ main ]
 
 jobs:
+  compile:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Test debug
+      run: |
+         ./scripts/dr.sh "rm -rf build_linux_debug"
+         ./scripts/dr.sh "mkdir build_linux_debug; cd build_linux_debug; cmake .. -GNinja -DCMAKE_BUILD_TYPE=Debug; ninja"
+
   debug:
 
     runs-on: ubuntu-latest
diff --git a/include/agglomeration_handler.h b/include/agglomeration_handler.h
index 1b75de3f..b273e6d3 100644
--- a/include/agglomeration_handler.h
+++ b/include/agglomeration_handler.h
@@ -754,9 +754,9 @@ class AgglomerationHandler : public Subscriptor
 
   ////////////////////////////////////////////////////////
 
-  SmartPointer<const Triangulation<dim, spacedim>> tria;
+  ObserverPointer<const Triangulation<dim, spacedim>> tria;
 
-  SmartPointer<const Mapping<dim, spacedim>> mapping;
+  ObserverPointer<const Mapping<dim, spacedim>> mapping;
 
   std::unique_ptr<FESystem<dim, spacedim>> euler_fe;
 
diff --git a/include/multigrid_amg.h b/include/multigrid_amg.h
index 11c40bc1..069e27de 100644
--- a/include/multigrid_amg.h
+++ b/include/multigrid_amg.h
@@ -479,7 +479,7 @@ namespace dealii
     /**
      * Sequence of transfer operators, stored as pointers to Trilinos matrices.
      */
-    MGLevelObject<SmartPointer<TrilinosWrappers::SparseMatrix>>
+    MGLevelObject<ObserverPointer<TrilinosWrappers::SparseMatrix>>
       transfer_matrices;
 
     /**