Bug: Fail on import

[hundredpinbowling]

1. OS: Fedora 41 GNU/Linux
2. Anki version: 24.11 from Flatpak

Cropro fails when trying to import large amounts of cards from another profile. It works when selecting only a few cards, but when select thousands of cards, I get the following error.

Anki 24.11 (87ccd24e) (src) (ao)
Python 3.12.8 Qt 6.8.1 PyQt 6.8.0
Platform: Linux-6.12.10-200.fc41.x86_64-x86_64-with-glibc2.40

Traceback (most recent call last):
  File "/app/lib/python3.12/site-packages/aqt/taskman.py", line 144, in _on_closures_pending
    closure()
  File "/app/lib/python3.12/site-packages/aqt/taskman.py", line 88, in <lambda>
    lambda future: self.run_on_main(lambda: on_done(future))
                                            ^^^^^^^^^^^^^^^
  File "/app/lib/python3.12/site-packages/aqt/taskman.py", line 108, in wrapped_done
    on_done(fut)
  File "/app/lib/python3.12/site-packages/aqt/operations/__init__.py", line 117, in wrapped_done
    self._failure(exception)
  File "/home/user/.var/app/net.ankiweb.Anki/data/Anki2/addons21/1772763629/cropro.py", line 470, in on_failure
    raise ex
  File "/usr/lib/python3.12/concurrent/futures/thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/lib/python3.12/site-packages/aqt/operations/__init__.py", line 108, in wrapped_op
    return self._op(mw.col)
           ^^^^^^^^^^^^^^^^
  File "/home/user/.var/app/net.ankiweb.Anki/data/Anki2/addons21/1772763629/cropro.py", line 484, in <lambda>
    op=lambda col: self._importer.import_notes(
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/user/.var/app/net.ankiweb.Anki/data/Anki2/addons21/1772763629/note_importer.py", line 217, in import_notes
    return col.merge_undo_entries(pos)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/lib/python3.12/site-packages/anki/collection.py", line 1057, in merge_undo_entries
    return self._backend.merge_undo_entries(target)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/lib/python3.12/site-packages/anki/_backend_generated.py", line 266, in merge_undo_entries
    raw_bytes = self._run_command(3, 11, message.SerializeToString())
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/lib/python3.12/site-packages/anki/_backend.py", line 172, in _run_command
    raise backend_exception_to_pylib(err)
anki.errors.InvalidInput: target undo op not found

===Add-ons (active)===
(add-on provided name [Add-on folder, installed at, version, is config changed])
AJT CroPro  Cross Profile Search and Import ['1772763629', 2024-09-20T03:36, 'None', mod]

===IDs of active AnkiWeb add-ons===
1772763629

[tatsumoto-ren]

Apparently, Anki just can't handle so many notes at the same time. I remember @dae said that there's a limit on how many undo entries col.merge_undo_entries(pos) can merge, but here there's only one operation between add_custom_undo_entry and merge_undo_entries, so that's confusing to me.

pos = col.add_custom_undo_entry(f"{ADDON_NAME_SHORT}: import {len(notes)} notes")
col.add_notes(requests)
return col.merge_undo_entries(pos)

The add-on uses col.add_notes() instead of col.add_note() exactly to avoid such issues. If you know a workaround, please share.

[dae]

My guess is some other DB op was interleaved between those lines, which could happen if the other caller was not using a collection op to ensure the ops are serialized. TRACESQL=1 might give a hint.

[hundredpinbowling]

My guess is some other DB op was interleaved between those lines, which could happen if the other caller was not using a collection op to ensure the ops are serialized. TRACESQL=1 might give a hint.

I tried to replicate the error by downloading a huge deck (Ultimate Birds - Images and sounds) and using cropro to import it. For whatever reason, copro had no problems importing 500 cards at a time.
I am not comfortable sharing the TRACESQL log with my main deck as I don't want to dox my cards.