exception text: clarify error message

[bobertlo]

The default error message is often invoked from running dvc pull and
in this case it is generally caused by not pushing to the remote. I
spent some time thinking about a replacement message and this seems to
be the most appropriate text I could think of.

Fixes #4316

• ❗ I have followed the Contributing to DVC checklist.

• 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.
  pull: add troubleshooting hints for failed command dvc.org#1660

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

[bobertlo]

I guess I will admit this does not "solve" the original issue. This error message always really bothered me though :)

[bobertlo]

I edited this to print a link to the troubleshooting page, edited in iterative/dvc.org#1671 with a short explanation of common problems.

[efiop]

The cache question seems unclear, how about just:

Suggested change

	"Checkout failed for following targets:\n{}\nIs your "
	"cache up to date?\n{}".format(
	"Checkout failed for following targets:\n{}\n"
	"Visit {} for more info.".format(

?

[skshetry]

"Visit {} for more info." sounds like holding a user hostage. We do need better exception message, which can be done by making _fetch and _checkout collaborate with each other, but making CheckoutError message generic is not a solution, it only adds confusion.

[efiop]

@skshetry Good point. Maybe for a lack of better message (because a more advanced approach is needed), let's just append "Vinit {} for more info"(or someting like that) to the old message? Just in the interest of time, since the proper-proper solution will require quite a bit more effort.

[bobertlo]

@efiop I was sort of thinking the same thing myself. I updated it to that and removed the "Fixes #4316" since that issue goes deeper than this. I think other changes are unrelated to this PR at this point?

Also I should note the link is live on dvc.org now.

[skshetry]

@efiop, yeah, that sounds good. But let's keep the issue open.

[bobertlo]

I suppose the errors provided during fetch are pretty clear. I mainly did not like the 'did you forget to fetch?' message. I can change this one I get near a terminal again.

[bobertlo]

@efiop Okay, made that exact change. I agree that since we're linking to the troubleshooting page we don't need anything more than the above error messages in the context.

[bobertlo]

Should checkout be called automatically from `dvc pull` even if fetch fails? If it stops there, fetch and checkout can just have proper error messages for themselves. Otherwise, yes they will need to collaborate.

…

On Mon, 10 Aug 2020 at 10:45, Saugat Pachhai ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In dvc/exceptions.py <#4339 (comment)>: > + "Checkout failed for following targets:\n{}\nIs your " + "cache up to date?\n{}".format( "Visit {} for more info." sounds like holding a user hostage. We do need better exception message, which can be done by making _fetch and _checkout collaborate with each other, but making CheckoutError message generic is not a solution, it only adds confusion. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#4339 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAGWHGPZ3RTWPDNGMFPELB3SAAIZXANCNFSM4PU6GRVA> .

[efiop]

Thanks @bobertlo !