2. Checks that all Git and database operations have completed.
Based on the information above, if running a build in Bamboo that has "Source Code Checkout" task using a Stash repository, this build should have no problems on completing the cloning task before Stash going on Maintenance mode.
However, when Stash is in Maintenance mode by Using Stash DIY Backup documentation, the same Bamboo build does not happens and the following error gets thrown:
It would be interesting on having a feature in Bamboo that when a Repository host "Stash" is selected, prior running a "Source Code Checkout" task, Bamboo would call a REST API requesting Stash status and, in case, the same returns PAUSED, MAINTENANCE the build in Bamboo would stop and a notification message will explain appropriated the reason.