When a Pull request is merged, Bitbucket must check all Pull requests open for the given destination branch to ensure that all other Pull Requests are still in a consistent state, and update them if they are not. While this check is happening, all other Pull request merging is temporarily locked until the Pull requests have all been checked and updated.
On a Repository with many (50+) open Pull requests against the same branch, users may experience the following behavior:
- A user merges any given Pull request, this one will be pretty quick
- Any subsequent attempt to merge a different Pull request will take a little while in relation to the total number of open Pull requests against that branch.
As a workaround, fewer Pull requests against the same branch will result in quicker merges. The Bitbucket team is aware of this issue and is investigating ways to improve this essential process.