message: Fix branch matching to work with GitHub Actions and BuildKite
diff: @@ -22,15 +22,18 @@ clone() {
  }
  # Try the PR author's branch in case it exists on the deps as well.
  -# First we check if BUILDKITE_BRANCH is defined,
  +# First we check if GITHUB_HEAD_REF is defined,
  +# Then we check if BUILDKITE_BRANCH is defined,
  # if it isn't we can assume this is a Netlify build
  -if [ -z ${BUILDKITE_BRANCH+x} ]; then
  +if [ -n ${GITHUB_HEAD_REF+x} ]; then
  + head=$GITHUB_HEAD_REF
  +elif [ -n ${BUILDKITE_BRANCH+x} ]; then
  + head=$BUILDKITE_BRANCH
  +else
  # Netlify doesn't give us info about the fork so we have to get it from GitHub API
  apiEndpoint="https://api.github.com/repos/matrix-org/matrix-react-sdk/pulls/"
  apiEndpoint+=$REVIEW_ID
  head=$(curl $apiEndpoint | jq -r '.head.label')
  -else
  - head=$BUILDKITE_BRANCH
  fi
  # If head is set, it will contain either:
  @@ -39,12 +42,18 @@ fi
  # We can split on `:` into an array to check.
  BRANCH_ARRAY=(${head//:/ })
  if [[ "${#BRANCH_ARRAY[@]}" == "1" ]]; then
  - clone $deforg $defrepo $BUILDKITE_BRANCH
  + clone $deforg $defrepo $head
  elif [[ "${#BRANCH_ARRAY[@]}" == "2" ]]; then
  clone ${BRANCH_ARRAY[0]} $defrepo ${BRANCH_ARRAY[1]}
  fi
  +
  # Try the target branch of the push or PR.
  +if [ -n ${GITHUB_BASE_REF+x} ]; then
  + clone $deforg $defrepo $GITHUB_BASE_REF
  +elif [ -n ${BUILDKITE_PULL_REQUEST_BASE_BRANCH+x} ]; then
  clone $deforg $defrepo $BUILDKITE_PULL_REQUEST_BASE_BRANCH
  +fi
  +
  # Try HEAD which is the branch name in Netlify (not BRANCH which is pull/xxxx/head for PR builds)
  clone $deforg $defrepo $HEAD
  # Use the default branch as the last resort.
  