VersionControl:PRs/magenta/460

magenta#460: Merge sheet: a stacked PR whose base merged says to rebase, not "has no … here"

State	🟣 merged 2026-11-11 10:09:58
Worked on by	magent, justin
Moods	#interfaces
Deploy	redeploy maybelle (memory-lane); no migrations
Branch	magent/merge-base-gone → main, by magent-cryptograss
Opened · last pushed	2026-11-10 14:14:35 · 2026-11-10 14:14:22

Justin, 10 Nov (#interfaces): pressing Merge on #453 said "magenta has no magent/candidates here". #453 was stacked on #451's branch. When #451 merged, githouse moved that branch to `refs/merged/`, which left the sheet nothing to merge into. Justin: "Can we have a more coherent error in that situation then?"

The sheet now says why and what to do:

- **The base merged or was closed:** "magenta#453 is built on magent/candidates, which has merged since, so there is nothing to merge it into. Its author rebases it onto main and points its pull request at main; then it can merge." It says "was closed" if the base was deleted without merging. The branch it names to rebase onto is the repository's deploy branch, or main.
- **Base missing for any other reason:** "magenta#N is to merge into X, and githouse has no magenta:X".
- **githouse doesn't hold the branch at all:** previously "githouse has no magenta:B". Now it adds: "its author pushes it to githouse (the hunter remote), then it can merge here". #453 was also in this state until I pushed it this morning.

**Tests:** new `test_one_stacked_on_a_branch_that_merged_says_to_rebase` checks the exact words. The full suite passes: 1,949 tests OK.

Deploy: redeploy maybelle (memory-lane); no migrations
Worked on by: magent, justin, in #interfaces