add: meaningful message upon adding overlapping paths

[pared]

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Fixes #3218

[pared]

Before:

After:

[efiop]

Let's do it a bit differently. Let's only keep OverlappingOutputPathsError, but raise it with specific message instead of hardcoding it into the exception class itself. That way we won't spawn new entities and it will be nicely catchable from outside if needed 🙂

[pared]

Yeah, makes sense

[efiop]

It is better to move a line down if you have \n. E.g.

"Cannot add '{out}', because it is overlapping with other "
"DVC tracked output: '{parent}'.\n"
"To include '{out}' in ..."

much easier to comprehend that way. Or was it black who did that?

[pared]

nah, black gets in the way only when lines do not match, I probably did that to save some lines :P

[efiop]

Suggested change

	except OverlappingOutputPathsError as e:
	except OverlappingOutputPathsError as exc:

DS and others complain about such naming.

[efiop]

Also please create a new line after \n here.

[efiop]

@pared Also check the tests, please.

[efiop]

minor: Please use consistent formatting. You skip trailing space in the first line but add it in the second one. IIRC prefered way to have a trailing space rather than a leading space. CC @jorgeorpinel

[jorgeorpinel]

Agree about consistency. Idk what's preferred though, I used to put trailing space last but later I noticed most of you use trailing first so rn there's a mix throughout docs. Maybe trailing space first is best because it makes it extra obvious that it's a continuation string? Up to you, I just rec to be consistent (available to review all existing strings once you decide, please lmk).

[shcheklein]

minor: we use sometimes outs sometimes outputs/output in this PR - would be probably good to use one of those consistently (probably output/outputs to avoid slang-slang)