diff --git a/.github/actions/4d-test-libs/action.yml b/.github/actions/4d-test-libs/action.yml
index 01844f595b6..6be2772cc70 100644
--- a/.github/actions/4d-test-libs/action.yml
+++ b/.github/actions/4d-test-libs/action.yml
@@ -35,7 +35,7 @@ runs:
           excludes+='|^std.experimental.allocator.building_blocks.allocator_list'
         fi
 
-        ctest -j$N --output-on-failure -E "$excludes" --timeout 120
+        ctest -j1 -V --output-on-failure -E "$excludes" --timeout 120
 
     - name: 'Windows: Run defaultlib unittests & druntime integration tests'
       if: runner.os == 'Windows'
@@ -51,4 +51,4 @@ runs:
         call "%LDC_VSDIR%\Common7\Tools\VsDevCmd.bat" -arch=${{ matrix.arch }} || exit /b
         echo on
         cd build || exit /b
-        ctest -j4 --output-on-failure -E "dmd-testsuite|lit-tests|ldc2-unittest" --timeout 120 || exit /b
+        ctest -j1 -V --output-on-failure -E "dmd-testsuite|lit-tests|ldc2-unittest" --timeout 120 || exit /b
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 758ccbaffed..687d3cc899e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -147,6 +147,13 @@ jobs:
         with:
           submodules: true
           fetch-depth: 50
+
+      - name: Check dash
+        shell: bash
+        run: |
+          /bin/sh --version || true
+          dpkg -s dash || true
+
       - name: Install prerequisites
         if: |
           !startsWith(matrix.container_image, 'alpine')
@@ -190,6 +197,13 @@ jobs:
         uses: ./.github/actions/4c-test-dmd
         with:
           arch: ${{ matrix.arch }}
+
+      - name: Check apk tool
+        shell: bash
+        run: |
+          command -v apk || true
+          apk --version || true
+
       - name: Run defaultlib unittests & druntime integration tests
         if: success() || failure()
         uses: ./.github/actions/4d-test-libs
diff --git a/runtime/druntime/test/exceptions/Makefile b/runtime/druntime/test/exceptions/Makefile
index 7565e425060..05237caccad 100644
--- a/runtime/druntime/test/exceptions/Makefile
+++ b/runtime/druntime/test/exceptions/Makefile
@@ -3,11 +3,16 @@ ifdef IN_LDC
 include ../../../../dmd/osmodel.mak
 endif
 
+$(info $(shell which apk &>/dev/null; echo $$?))
+$(info $(shell which apk &>/dev/null && echo 1 ; echo $$?))
+$(info $(shell command -v apk &>/dev/null ; echo $$?))
+$(info $(shell command -v apk &>/dev/null && echo 1 ; echo $$?))
+
+
 ifeq ($(OS),linux)
     # FIXME: detect musl libc robustly; just checking Alpine Linux' apk tool for now
-    ifeq (1,$(shell which apk &>/dev/null && echo 1))
-        IS_MUSL:=1
-    endif
+    IS_MUSL != command -v apk &>/dev/null && echo 1
+    $(warning ~~~ musl $(IS_MUSL))
 endif
 
 TESTS=stderr_msg unittest_assert invalid_memory_operation static_dtor \
@@ -65,6 +70,8 @@ endif
 ifeq ($(OS),windows)
     TESTS+=winstack
 endif
+
+$(warning ~~~ All the tests are: $(TESTS))
 include ../common.mak
 
 $(ROOT)/line_trace.done: $(ROOT)/line_trace$(DOTEXE)