Submodule regression from 0.22 -> 0.23

[ChrisPenner]

Description

Hi folks! I noticed a regression recently that's been making it pretty difficult for me to use jj on one of my larger projects so I figured I'd try and narrow it down and get a report together.

jj has always happily ignored my git submodules and let me manage them using git without much trouble, however there's been a change between version 0.22.0 (which works well) to 0.23.0 which causes issues.

In 0.23.0 jj seems to start tracking submodules if you have a commit which mentions them, then it causes all sorts of problems where jj thinks you've got changes in your submodules, but you can't actually commit or ignore them no matter what you do. I'm having trouble pinning down how I got into that state, but I was able to reproduce the following workflow:

Steps to Reproduce the Problem

The following steps fail on 0.23.0, but work fine on 0.22.0

1. `git clone "git@github.com:unisoncomputing/share-api"
2. git submodule update --init --recursive
3. jj git init --colocate
4. cd unison && git checkout cp/batched-diffs (any branch other than trunk will do, we just need a change to commit)
   5.cd .. && git add -A && git commit -m "commit submodule"
5. jj status
6. jj abandon -r @-

Abandoned commit rzpynzsp a56fbf3d update submodule
Rebased 1 descendant commits onto parents of abandoned commits
Internal error: Failed to check out commit cee899b78e7d4a477c866636ae250ea692c585e7
Caused by:
1: Failed to remove file /Users/cpenner/dev/share-api/unison
2: Operation not permitted (os error 1)

$ jj status
Error: The working copy is stale (not updated since operation 853877ccb943).
Hint: Run `jj workspace update-stale` to update it.
See https://martinvonz.github.io/jj/latest/working-copy/#stale-working-copy for more information.

Expected Behavior

jj version 0.22.0 demonstrates the correct behaviour, it simply ignores the submodule and doesn't error or track files within it.

Actual Behavior

jj version 0.23.0 sometimes fails to check out changes which alter submodules, and sometimes tracks changes within them if there are git commits which have updated the submodule.

Specifications

• Platform: OSX
• Version: 0.23.0

Thanks for all your work folks, love the tool!

[yuja]

Sorry, there was a bug in submodule handling. The fix will be included in the next release.
#4825

[ChrisPenner]

Great thanks!! 🙏