diff --git a/.github/workflows/main-app.yml b/.github/workflows/main-app.yml
index 82067831b..0f45a5bf8 100644
--- a/.github/workflows/main-app.yml
+++ b/.github/workflows/main-app.yml
@@ -59,17 +59,8 @@ jobs:
 
     - name: Debug CI configure
       run: >-
-        cmake
-        -S ${{github.workspace}}/.github/workflows/testcpp
-        -B ${{github.workspace}}/build-testcpp
-        -DCMAKE_BUILD_TYPE=$BUILD_TYPE
-
-    - name: Debug CI build
-      working-directory: ${{github.workspace}}/build-testcpp
-      env:
-        VERBOSE: 1
-      run: |
-        cmake --build .
+        $CXX --std=c++20 $CXXFLAGS $(mpicxx --showme:compile) -c ${{github.workspace}}/.github/workflows/testcpp/test.cpp -o test.o
+        $CXX --std=c++20 $LDFLAGS $(mpicxx --showme:link) test.o -o test
 
     - name: Code make build dir
       run: mkdir -p ${{github.workspace}}/build