Stage: fix used_cache warning on no checksum

[pared]

• ❗ Have you followed the guidelines in the Contributing to DVC list?

• 📖 Check this box if this PR does not require documentation updates, or if it does and you have created a separate PR in dvc.org with such updates (or at least opened an issue about it in that repo). Please link below to your PR (or issue) in the dvc.org repo.

• ❌ Have you checked DeepSource, CodeClimate, and other sanity checks below? We consider their findings recommendatory and don't expect everything to be addressed. Please review them carefully and fix those that actually improve code or fix bugs.

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

[efiop]

This property should only return what is already computed, it shouldn't start computing it all over again.

See dvc/outpt/base.py:get_used_cache, where the issue rose. We check if not self.info there, while we should probably check if not self.checksum. Push shouldn't push uncommited changes, as it doesn't even have the cache for them in .dvc/cache.

[efiop]

Suggested change

	out=self, stage=self.stage.relpath
	out=self, stage=self.stage

same as above 🙂

[pared]

AFAIK it will result in dvc commit 'Stage file.dvc' ;)

[efiop]

@pared Oh, but then the upper warning is broken too, right?

[pared]

@efiop
I wouldn't say so: the upper message is pointing user to which stage particular output is associated to, while the lower one suggests command that can fix your situation. So in the upper one, its not crucial for stage to be printed just as relpath.

[efiop]

Maybe let's narrow it down to get_used_cache unit test for output?

[pared]

makes sense

[efiop]

Thanks!