Work around missing bazel features for rabbitmq docker build

Until
bazelbuild/bazel#17128 (comment)
is implemented, there is no clean way to override an erlang
package. So at least let's try doing our best, and just check
afterwards that it actually worked.

.github/workflows/rabbitmq-oci.yaml

@@ -79,9 +79,20 @@ jobs:
         working-directory: rabbitmq-server
         run: |
           sed -i"_orig" -E '/APP_VERSION/ s/3\.[0-9]+\.[0-9]+/${{ steps.load-rabbitmq-info.outputs.RABBITMQ_SHA }}/' rabbitmq.bzl
+          RULES_ERLANG_VERSION=$(bazel query --output=build //external:rules_erlang  | sed -r -n 's/^.*tag = "(.*)".*$/\1/p')
           bazelisk build :package-generic-unix \
             --config=rbe-${{ matrix.otp_major }} \
-            --override_repository rules_erlang~3.9.9~erlang_package~osiris=${{ github.workspace }}/osiris
+            --override_repository rules_erlang~$RULES_ERLANG_VERSION~erlang_package~osiris=${{ github.workspace }}/osiris
+
+          # rules_erlang version detection is not bullet-proof, so let's check that override did indeed work
+          set -o pipefail
+          if ! tar --list -f ./bazel-bin/package-generic-unix.tar.xz  | grep -F "plugins/osiris-${{ github.event.pull_request.head.sha || github.sha }}/ebin/osiris.app" ; then
+            echo "Failed to override osiris repo"
+            echo "Inferred repo name: rules_erlang~$RULES_ERLANG_VERSION~erlang_package~osiris"
+            echo "Repo name as seen after build:"
+            ls bazel-bin/external/ | grep osiris
+            exit 1
+          fi
 
       - name: Resolve generic unix package path
         run: |