Having trouble understanding --no-integrate-operation, --at-op, and snapshotting

[drieber]

I am trying to write some CLI tests that simulate concurrent jj invocations, using --no-integrate-operations and --at-op. I am having problems simulating file writes. It is as if the writes do not make it to the commits. I must be missing something very basic here. Below is a reproducer for the "issue" on the command-line. Notice how I write resolved to file, but the write appears to not make it to commit c3ff6ce6176163:

$ jj git init
Initialized repo in "."

$ echo start > file
$ jj describe -m start
Working copy  (@) now at: sxtvttts 7bc56340e55599 start
Parent commit (@-)      : zzzzzzzz 00000000000000 (empty) (no description set)

$ jj new -m child1
Working copy  (@) now at: wuruuxsn 8bbf66925e0f2c (empty) child1
Parent commit (@-)      : sxtvttts 7bc56340e55599 start
$ echo child1 > file

$ jj
@  wuruuxsn drieber@google.com 2026-08-06 12:51:20.000 -07:00 f66273a277aa7a
│  child1
○  sxtvttts drieber@google.com 2026-08-06 12:50:42.000 -07:00 7bc56340e55599
│  start
◆  zzzzzzzz root() 00000000000000

$ jj new -r s -m child2
Working copy  (@) now at: utzyuwrz 40532fe94097ed (empty) child2
Parent commit (@-)      : sxtvttts 7bc56340e55599 start
Added 0 files, modified 1 files, removed 0 files
$ echo child2 > file

$ jj
@  utzyuwrz drieber@google.com 2026-08-06 12:51:54.000 -07:00 47ecea25d34225
│  child2
│ ○  wuruuxsn drieber@google.com 2026-08-06 12:51:20.000 -07:00 f66273a277aa7a
├─╯  child1
○  sxtvttts drieber@google.com 2026-08-06 12:50:42.000 -07:00 7bc56340e55599
│  start
◆  zzzzzzzz root() 00000000000000

$ jj rebase -o w --no-integrate-operation
Rebased 1 commits to destination.
New conflicts appeared in 1 commits:
  utzyuwrz 238a28b28347ed (conflict) child2
Hint: To resolve the conflicts, start by creating a commit on top of
the conflicted commit:
  jj new utzyuwrz
Then use `jj resolve`, or edit the conflict markers in the file directly.
Once the conflicts are resolved, you can inspect the result with `jj diff`.
Then run `jj squash` to move the resolution into the conflicted commit.
Operation left uncommitted because --no-integrate-operation was requested: 6b876b745483

$ echo resolved > file
$ jj describe -m foo1 --at-op 6b876b745483 --no-integrate-operation
Operation left uncommitted because --no-integrate-operation was requested: f454df762ab3

$ jj op integrate f454df762ab3
$ jj workspace update-stale
Concurrent modification detected, resolving automatically.
Working copy  (@) now at: utzyuwrz/1 c3ff6ce6176163 (divergent) (conflict) foo1
Parent commit (@-)      : wuruuxsn f66273a277aa7a child1
Added 0 files, modified 1 files, removed 0 files
Warning: There are unresolved conflicts at these paths:
file    2-sided conflict
Updated working copy to fresh commit c3ff6ce61761

$ jj op log
@    c25b20415a52 drieber@rieber.svl.corp.google.com default@ 33 seconds ago (2026-08-06 12:56:23.943 -07:00), lasted 7 milliseconds
├─╮  reconcile divergent operations
│ │  args: jj workspace update-stale
○ │  f454df762ab3 drieber@rieber.svl.corp.google.com default@ 1 minute ago (2026-08-06 12:55:37.476 -07:00), lasted 25 milliseconds
│ │  describe commit 238a28b28347edcde23c71af63f2b865ef7be179
│ │  args: jj describe -m foo1 --at-op 6b876b745483 --no-integrate-operation
○ │  6b876b745483 drieber@rieber.svl.corp.google.com default@ 4 minutes ago (2026-08-06 12:52:32.831 -07:00), lasted 25 milliseconds
│ │  rebase commit 47ecea25d34225bc797bf47ccaf5824b4e139cf8 and descendants
│ │  args: jj rebase -o w --no-integrate-operation
│ ○  a06da4466971 drieber@rieber.svl.corp.google.com default@ 33 seconds ago (2026-08-06 12:56:23.884 -07:00), lasted 25 milliseconds
├─╯  snapshot working copy
│    args: jj workspace update-stale
○  cb221f5c88b7 drieber@rieber.svl.corp.google.com default@ 5 minutes ago (2026-08-06 12:51:54.323 -07:00), lasted 25 milliseconds
│  snapshot working copy
│  args: jj log
○  241527af9f94 drieber@rieber.svl.corp.google.com default@ 5 minutes ago (2026-08-06 12:51:41.262 -07:00), lasted 16 milliseconds
│  new empty commit
│  args: jj new -r s -m child2
○  b90b3f960e64 drieber@rieber.svl.corp.google.com default@ 5 minutes ago (2026-08-06 12:51:20.085 -07:00), lasted 25 milliseconds
│  snapshot working copy
│  args: jj log
○  6670db71dba3 drieber@rieber.svl.corp.google.com default@ 6 minutes ago (2026-08-06 12:50:56.856 -07:00), lasted 25 milliseconds
│  new empty commit
│  args: jj new -m child1
○  1770fbfa4804 drieber@rieber.svl.corp.google.com default@ 6 minutes ago (2026-08-06 12:50:42.033 -07:00), lasted 15 milliseconds
│  describe commit 7cfe4683b4789338606bb63857a2d5397285a239
│  args: jj describe -m start
○  47aac38f9fa0 drieber@rieber.svl.corp.google.com default@ 6 minutes ago (2026-08-06 12:50:41.977 -07:00), lasted 24 milliseconds
│  snapshot working copy
│  args: jj describe -m start
○  a7f5aeac9952 drieber@rieber.svl.corp.google.com 6 minutes ago (2026-08-06 12:50:16.692 -07:00), lasted 24 milliseconds
│  add workspace 'default'
○  000000000000 root()

$ jj
@  utzyuwrz/1 drieber@google.com 2026-08-06 12:55:37.000 -07:00 c3ff6ce6176163 (divergent) (conflict)
│  foo1
○  wuruuxsn drieber@google.com 2026-08-06 12:51:20.000 -07:00 f66273a277aa7a
│  child1
│ ○  utzyuwrz/0 drieber@google.com 2026-08-06 12:56:23.000 -07:00 f898a3f816c134 (divergent)
├─╯  child2
○  sxtvttts drieber@google.com 2026-08-06 12:50:42.000 -07:00 7bc56340e55599
│  start
◆  zzzzzzzz root() 00000000000000

$ jj file show -r c3ff6ce6176163 file
<<<<<<< conflict 1 of 1
%%%%%%% diff from: sxtvttts 7bc56340 "start" (parents of rebased revision)
\\\\\\\        to: wuruuxsn f66273a2 "child1" (rebase destination)
-start
+child1
+++++++ utzyuwrz 47ecea25 "child2" (rebased revision)
child2
>>>>>>> conflict 1 of 1 ends

$ cat file
<<<<<<< conflict 1 of 1
%%%%%%% diff from: sxtvttts 7bc56340 "start" (parents of rebased revision)
\\\\\\\        to: wuruuxsn f66273a2 "child1" (rebase destination)
-start
+child1
+++++++ utzyuwrz 47ecea25 "child2" (rebased revision)
child2
>>>>>>> conflict 1 of 1 ends

[drieber]

Please note that I am trying to create divergence on purpose. My goal is to use --no-integrate-operation and --at-op=<OPERATION> and jj op integrate in a sequence similar to the above to create divergent commits. I want the divergent commits to have different trees.

[drieber]

This discussion started in https://discord.com/channels/968932220549103686/969291218347524238/1535006240525123666.

BTW, I think the interesting behavior can be seen in a much much much simpler reproducer than what I wrote in the description (but I did not want to loose that). Essentially the "surprising" (to me) behavior is that --at-operation implies --ignore-working-copy, which means you cannot easily build chains of operations with --no-integrate-operation + --at-operation if you want to also change files by writing to the filesystem directly.