Checking out 52913bcf as master...Skipping Git submodules setup$ [[ "$TRACE" ]] && set -x # collapsed multi-line command$ if [[ -z "$CI_COMMIT_TAG" ]]; then # collapsed multi-line command$ /build/build.shBuilding Heroku-based application using gliderlabs/herokuish docker image...invalid argument "/master:52913bcf53ad07bd6bd50b16201e6741de9bc6ff" for "-t, --tag" flag: invalid reference formatSee 'docker build --help'.ERROR: Job failed: exit code 1