A deleted backup wedges its swap-state entry permanently

[tony]

Summary

If a backup file is removed after a swap — tmpreaper, a manual clean, a wiped /tmp — revert fails on that entry and leaves it in the state file. Every later revert fails the same way, forever. There is no subcommand to forget an entry, so the state file has to be edited by hand.

Reproduction

run use-local --repo "$PWD" --cli cursor --no-preflight

rm -f "$SB/.cursor/"*.bak.mcp-swap-*

run revert --cli cursor

run revert --cli cursor

Expected

A missing backup is unrecoverable, so say so once and drop the entry — or offer a way to drop it. The config is already in whatever state the swap left it; keeping the entry does not help anyone.

Actual

Both runs print the same line and exit non-zero. The entry is never cleared:

[cursor] backup missing: <sandbox>/.cursor/mcp.json.bak.mcp-swap-20260809204121

References

• _cmd_revert missing-backup branch at v0.1.0a20