Non-actionable "conflicting changes in the working copy" message possible when changing to commit with different gitignore

[ilyagr]

Update: Yuya points out below this might be watchman-related. I did have both watchman and core.watchman.register_snapshot_trigger enabled during the reproduction.

Description

I can get a repo into a situation when I get a non-actionable message

$ jj next
Working copy now at: xqlkmt ccb2a0f (empty) (no description set)
Parent commit      : xuwtoq b814c10 2
Added 1 files, modified 1 files, removed 1 files
Warning: 1 of those updates were skipped because there were conflicting changes in the working copy.
Hint: Inspect the changes compared to the intended target with `jj diff --from ccb2a0fc5d87`.
Discard the conflicting changes with `jj restore --from ccb2a0fc5d87`.
$ jj diff --from ccb # No output
$ jj restore --from ccb2a0fc5d87
Nothing changed
$ cat qq
something
$  jj file show qq
something else

Steps to Reproduce the Problem

Start with the following repo state. You can also download jj-localignoretest.tar.gz.

The key point is that commit 2 has a file qq
with contents "something else" while commit 1 has a .gitignore that includes qq.
Then, you do jj new commit1.

$ jj log --patch --git
@  tsmuux ilyagr@users 26 seconds ago 8aacee6
│  (empty) (no description set)
│ ○  xuwtoq ilyagr@users 37 seconds ago b814c10
├─╯  2
│    diff --git a/.gitignore b/.gitignore
│    deleted file mode 100644
│    index b26b2efe69..0000000000
│    --- a/.gitignore
│    +++ /dev/null
│    @@ -1,1 +0,0 @@
│    -qq
│    diff --git a/qq b/qq
│    new file mode 100644
│    index 0000000000..3dfdc59b46
│    --- /dev/null
│    +++ b/qq
│    @@ -0,0 +1,1 @@
│    +something else
○  lzxkyw ilyagr@users 2 minutes ago 81435d5
│  1
│  diff --git a/.gitignore b/.gitignore
│  new file mode 100644
│  index 0000000000..b26b2efe69
│  --- /dev/null
│  +++ b/.gitignore
│  @@ -0,0 +1,1 @@
│  +qq
◆  zzzzzz root() 0000000

Then, do

$ echo something > qq
$ jj diff # No output, as expected.
$ jj next
Working copy now at: xqlkmt ccb2a0f (empty) (no description set)
Parent commit      : xuwtoq b814c10 2
Added 1 files, modified 1 files, removed 1 files
Warning: 1 of those updates were skipped because there were conflicting changes in the working copy.
Hint: Inspect the changes compared to the intended target with `jj diff --from ccb2a0fc5d87`.
Discard the conflicting changes with `jj restore --from ccb2a0fc5d87`.

Expected Behavior

An actionable message. (Haven't yet thought about what)

Actual Behavior

As already described above, following the instructions does not help

$ jj diff --from ccb # No output
$ jj restore --from ccb2a0fc5d87
Nothing changed
$ cat qq
something
$  jj file show qq
something else

Specifications

• Platform: aarch64-darwin
• Version: 0.26

[ilyagr]

Something similar happens on a case-insensitive filesystem (easy to get on Mac or Windows) for

○  rmvxwy ilyagr@users 38 seconds ago af02150
│  change case
│  Added regular file QQ:
│          1: third thing
│  Removed regular file qq:
│     1     : something else

if you jj new r-; jj new r.

Thanks to @jennings , who may or may not file another bug for this.

Aside: For Linux, there is https://www.brain-dump.org/projects/ciopfs/ for making case-insensitive filesystems, which I've never tried.

[ilyagr]

Also, an FR: the message could list the paths of problematic files (all of them, or a subset if there are many).

[yuja]

Can you test without watchman? I suspect our watchman integration doesn't handle skipped files properly.

[ilyagr]

Indeed, great point! I had it on, and running jj config set --repo core.fsmonitor "none" makes a difference.

Now, it acts as follows for the qq->QQ example. I'm still not sure I'm happy about it (the error message could be clearer), but it is definitely better than with Watchman.

🐟 jj log --patch -r next
○  rmvxwy ilyagr@users 18 minutes ago af02150
│  change case
~  Added regular file QQ:
           1: third thing
   Removed regular file qq:
      1     : something else
[22:49] macaw ~/tmp/jj-localignoretest <x>→<p|∅>
🐟 cat qq
something else
[22:49] macaw ~/tmp/jj-localignoretest <x>→<p|∅>
🐟 jj next
Working copy now at: qrpptt 58f48d5 (empty) (no description set)
Parent commit      : rmvxwy af02150 change case
Added 1 files, modified 0 files, removed 1 files
Warning: 1 of those updates were skipped because there were conflicting changes in the working copy.
Hint: Inspect the changes compared to the intended target with `jj diff --from 58f48d577324`.
Discard the conflicting changes with `jj restore --from 58f48d577324`.
[22:49] macaw ~/tmp/jj-localignoretest <r>→<q|∅>
🐟 cat qq
cat: qq: No such file or directory
[22:50] macaw ~/tmp/jj-localignoretest [1] <r>→<q|∅>
🐠 jj diff --from 58f
Removed regular file QQ:
   1     : third thing
[22:50] macaw ~/tmp/jj-localignoretest <r>→<q>
🐟 jj restore --from 58f
Created qrpptt cdc5bc8 (empty) (no description set)
Working copy now at: qrpptt cdc5bc8 (empty) (no description set)
Parent commit      : rmvxwy af02150 change case
Added 1 files, modified 0 files, removed 0 files
[22:50] macaw ~/tmp/jj-localignoretest <r>→<q|∅>
🐟 jj diff
[22:50] macaw ~/tmp/jj-localignoretest <r>→<q|∅>
🐟 cat qq
third thing

Note that the author of the mysterious Discord report on Windows says they have watchman disabled.