Agent does not verify requested commit-ish is in requested branch

[ticky]

Currently, if you manually trigger a build, specifying both a branch and a commit-ish, the Agent treats the specified commit-ish as though it were in the specified branch.

In cases where you require specific things to happen on specific branches (i.e. deploy from master), this can cause issues.

A workaround for now is to implement a check in your own build scripts;

if ! git branch -r --contains "${BUILDKITE_COMMIT}" | grep -q "origin/${BUILDKITE_BRANCH}" 2> /dev/null; then
  echo "The commit SHA ${BUILDKITE_COMMIT} was not found in ${BUILDKITE_BRANCH}. Exitting..."
  exit 1
fi

(thanks to Jacob from Envato for investigation of this issue)