diff --git a/.github/workflows/test-container.yml b/.github/workflows/test-container.yml
index a60c327..7aef50a 100644
--- a/.github/workflows/test-container.yml
+++ b/.github/workflows/test-container.yml
@@ -16,6 +16,9 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Show commit SHA
+        run: git rev-parse HEAD
+
       - name: Show Docker version
         run: docker version
 
diff --git a/Dockerfile b/Dockerfile
index 125f012..76f90d9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,12 @@
 # ------------------------------------------------------------
 # Base image selector — overridden by Makefile
 # ------------------------------------------------------------
-ARG BASE_IMAGE=archlinux:latest
+ARG BASE_IMAGE
 FROM ${BASE_IMAGE}
 
+RUN echo "BASE_IMAGE=${BASE_IMAGE}" && \
+    cat /etc/os-release || true
+
 # ------------------------------------------------------------
 # Nix environment defaults
 #
diff --git a/scripts/test/test-container.sh b/scripts/test/test-container.sh
index 5f60ec5..1d018fd 100755
--- a/scripts/test/test-container.sh
+++ b/scripts/test/test-container.sh
@@ -7,6 +7,8 @@ echo
 echo "------------------------------------------------------------"
 echo ">>> Testing container: $IMAGE"
 echo "------------------------------------------------------------"
+echo "[test-container] Inspect image metadata:"
+docker image inspect "$IMAGE" | sed -n '1,40p'
 
 echo "[test-container] Running: docker run --rm --entrypoint pkgmgr $IMAGE --help"
 echo