Vim swap file retention after a failed upgrade

Answer

When Vim terminates unexpectedly—whether due to a crashed upgrade, a power loss, or a forced kill—it does not delete its swap file (.swp). The file remains on disk to allow recovery of any unsaved changes.

Confirmed facts

• The swap file is created when a buffer is first edited and is only removed when Vim closes the buffer cleanly (via :quit, :wq, or similar).
• If Vim is killed before it can execute its cleanup routine, the .swp file stays behind.
• On the next edit of the file, Vim detects the existing swap and shows the prompt "Found a swap file by the name …" offering options to recover, edit anyway, or quit.
• The :checktime command only checks the underlying file’s modification timestamp; it does not trigger swap‑file deletion.
• Manual removal of the .swp file is required once you have either recovered the changes or decided to discard them.

Likely explanation for a failed upgrade

During a package upgrade, the Vim binary may be replaced while an editing session is still running. If the upgrade script is interrupted or the system is forced to reboot, the Vim process can be terminated without executing its normal exit handlers. Consequently, the swap file that was active at that moment is left behind.

Steps to recover or discard the swap file

1. Open the file again (e.g., vim myfile.txt). You will see the recovery prompt.
2. If you need to retrieve unsaved changes:
   • Choose Recover (press R) or run :recover after opening the file.
   • Verify the recovered content, then save it with :w.
   • After saving, quit Vim (:q).
   • Finally delete the swap file: rm myfile.txt.swp.
3. If you do not need the unsaved changes (or you have already saved them elsewhere):
   • Choose Delete at the prompt, or quit Vim and manually run rm myfile.txt.swp.

When to ask for a missing diagnostic detail

The only detail that changes the recommendation is whether you need to attempt recovery of unsaved edits. If you are unsure, run:

vim -r myfile.txt   # opens the file in recovery mode without the prompt

Inspect the buffer; if it contains valuable changes, save them before deleting the swap. If the buffer looks empty or matches the saved file, you can safely delete the swap.