Add compat skip message

Dockerfile

@@ -6,6 +6,8 @@ FROM $REPO_ARCH/ruby:2.7-alpine3.15
 ARG GIT_BRANCH
 ARG GIT_REPOSITORY
 
+ARG REPO_ARCH
+
 # Tell rails to serve static files
 ENV RAILS_SERVE_STATIC_FILES="true"
 ENV RAILS_ENV="production"
@@ -19,7 +21,7 @@ RUN apk add --no-cache whois nodejs yarn ca-certificates git bash \
   gcc g++ make libc-dev file sed \
   imagemagick protobuf-dev libpq ffmpeg icu-dev libidn-dev yaml-dev \
   readline-dev postgresql-dev curl tini python3 shared-mime-info && \
-  if [ "$REPO_ARCH" = "arm64v8" ]; then apk add libc6-compat; fi && \
+  if [ "${REPO_ARCH}" = "arm64v8" ]; then apk add libc6-compat; else echo "${REPO_ARCH} is not arm64v8, skipping compat"; fi && \
   update-ca-certificates
 
 # Create the mastodon user