`nbdime mergetool` error: `Invalid merge decision action: take_max`

[ryan-williams]

With latest release (4.0.2), I'm trying to rebase the single commit 070319d (@nbs.0) onto 745ed76 (@27), and getting:

Error: Invalid merge decision action: take_max

Terminal output seems fine

$ nbdime mergetool
Merging:
notebooks/tutorial_lightning.ipynb
notebooks/tutorial_multiworker.ipynb
notebooks/tutorial_pytorch.ipynb

Normal merge conflict for 'notebooks/tutorial_lightning.ipynb':
  {local}: modified file
  {remote}: modified file
[I nbdimeserver:431] Listening on 127.0.0.1, port 52635
[I webutil:29] URL: http://127.0.0.1:52635/mergetool
[I nbdimeserver:320] Closing server on remote request (1)
notebooks/tutorial_lightning.ipynb seems unchanged.
Was the merge successful [y/n]? n

I see take_max is a possible action in decisions.py but not handled in decisions.ts.

[vidartf]

Oh, that looks like an oversight. Are you using the merge driver as well? What commands did you run before the mergetool command? Just a git rebase command?

[ryan-williams]

Yes, I'm able to repro it like this:

git clone -b nbs.0 https://github.com/ryan-williams/TileDB-SOMA-ML && cd TileDB-SOMA-ML
python -m venv .venv && . .venv/bin/activate
pip install nbdime && nbdime config-git --enable
git rebase --onto 745ed76 HEAD^  # Encounters .ipynb conflicts
nbdime mergetool  # ❌ Opens browser with error like in screenshot above