Use _unstack_once for valid dask and sparse versions

[Illviljan]

• Requires Add version variable for optional imports in pycompat #5314
• Passes pre-commit run --all-files

[pep8speaks]

Hello @Illviljan! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2021-05-17 21:56:42 UTC

[Illviljan]

pint doesn't seem to be playing nice still @max-sixty. Seems some of your issues from #4746 are still there? Eventhough some of the issues in #4751 seems to have been solved.

[max-sixty]

pint doesn't seem to be playing nice still @max-sixty. Seems some of your issues from #4746 are still there? Eventhough some of the issues in #4751 seems to have been solved.

@keewis any thoughts?

One (kinda bad) idea would be to branch on whether pint was installed — presumably if it's not installed then it can't cause the import issues. But changing dask performance based on whether pint is installed is not great!

[keewis]

yep, to really fix this we would have to change pint. I think it would be worth verifying whether we can check the interface (with hasattr) instead of type checking using isinstance, though.

[max-sixty]

yep, to really fix this we would have to change pint. I think it would be worth verifying whether we can check the interface (with hasattr) instead of type checking using isinstance, though.

Great, that could be a good workaround. What attr would we check for?

[Illviljan]

@keewis any idea what it means when only 1 check has been run?

[keewis]

github actions currently has "degraded performance" (earlier today it was a "major outage")

[max-sixty]

Looks great! Let's merge on green. Feel free to add a whatsnew @Illviljan !

[max-sixty]

Great @Illviljan ! Feel free to add a whatsnew in a different PR — this is good news for lots of dask users