fix: don't try to tag oci-archive destinations

This stops an error when building simple `FROM xxx` images.

Signed-off-by: Adam Eijdenberg <[email protected]>

Author: aeijdenberg

imagebuildah/stage_executor.go

@@ -2119,6 +2119,12 @@ func (s *StageExecutor) tagExistingImage(ctx context.Context, cacheID, output st
 	if err != nil {
 		return "", nil, fmt.Errorf("copying image %q: %w", cacheID, err)
 	}
+
+	// If the destination isn't container storage, then we're done and can return early
+	if dest.Transport().Name() != is.Transport.Name() {
+		return cacheID, nil, nil
+	}
+
 	manifestDigest, err := manifest.Digest(manifestBytes)
 	if err != nil {
 		return "", nil, fmt.Errorf("computing digest of manifest for image %q: %w", cacheID, err)

tests/bud.bats

@@ -8479,3 +8479,12 @@ _EOF
   run_buildah build --layers -f $BUDFILES/from-scratch/Containerfile2 $BUDFILES/from-scratch/
   assert "$output" !~ "Using cache"
 }
+
+@test "build-to-oci-archive-succeeds-with-simple-from-build-file" {
+  local out_file=${TEST_SCRATCH_DIR}/simple-busybox-oci.tar
+
+  run_buildah build -f <(echo 'FROM busybox') --tag=oci-archive:"${out_file}"
+
+  # confirm tar is written
+  stat "${out_file}"
+}