Currently when a docs build is triggered for a branch, the latest version of that branch will always be used. This can cause problem if a subsequent build adds meta-data and hasn't completed in time.
This happened with commit f5f888dbdd1b0398efa0292da06b56de03797670 which triggered a docs build that actually used afcc780e61167b55ecc599c240ef8f57de75d2bc.
If we pass the sha in when we trigger the build, we should be able to git reset the branch before starting Antora.