fix: keep a command with default cmake generator

.github/workflows/build-check.yaml

@@ -28,7 +28,9 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Build & run tests
-        run: make test
+        run: |
+          CMAKE_GENERATOR=Ninja make set_gen
+          make test
   
   check_format:
     name: Check codebase format with clang-format
@@ -59,6 +61,7 @@ jobs:
 
     - name: Build project
       run: |
+        CMAKE_GENERATOR=Ninja make set_gen
         make all
         ./build/tests/z_modular_test $Z_FEATURE_PUBLICATION $Z_FEATURE_SUBSCRIPTION $Z_FEATURE_QUERYABLE $Z_FEATURE_QUERY
       continue-on-error: true

GNUmakefile

@@ -77,7 +77,7 @@ all: make
 $(BUILD_DIR)/Makefile:
 	mkdir -p $(BUILD_DIR)
 	echo $(CMAKE_OPT)
-	cmake $(CMAKE_OPT) -B $(BUILD_DIR) -G $(CMAKE_GENERATOR)
+	cmake $(CMAKE_OPT) -B $(BUILD_DIR)
 
 make: $(BUILD_DIR)/Makefile
 	cmake --build $(BUILD_DIR)
@@ -88,6 +88,9 @@ install: $(BUILD_DIR)/Makefile
 test: make
 	ctest --verbose --test-dir build
 
+set_gen:
+	cmake $(CMAKE_OPT) -B $(BUILD_DIR) -G $(CMAKE_GENERATOR)
+
 crossbuilds: $(CROSSBUILD_TARGETS)
 
 DOCKER_OK := $(shell docker version 2> /dev/null)