get_next_release only considers builds that are COMPLETE, BUILDING, or DELETED when choosing a base release to increment. If there are a lot of recent builds in other states, it can return a release value that already exists.
Metadata Update from @mikem: - Custom field Size adjusted to None - Issue set to the milestone: 1.36
Breadcrumbs
In #4413, we added the strict parameter to the new_build call in get_next_build
Metadata Update from @mikem: - Issue tagged with: testing-custom
Metadata Update from @mfilip: - Issue tagged with: testing-done
Commit 249d84bb fixes this issue
This issue has been migrated to Fedora Forge: https://forge.fedoraproject.org/koji/koji/issues/4490
Please continue any further discussion there.