There is no indicator in the UI for why hitting a button fails, like how it did for this merge attempt.
On the server side, this was the output:
2025/12/10 08:04:52 ERRO knot/server/xrpc: failed to merge handler=Merge
error=
│ patch application failed: error: src/components/Post/MastodonHtmlContent.tsx: does not exist in index
│ error: src/lib/strings/html-sanitizer.ts: does not exist in index
│ hint: Use 'git am --show-current-patch=diff' to see the failed patch
The invalid patch was probably accepted during the creation of the pull request, so that's also an important bug.