cabal new-path

[angerman]

I find myself often needing paths for cabals new-build artifacts. stack has a path command, that allows to retrieve information about directories for the current setup.

A cabal new-path command providing similar functionality would be quite useful.

E.g.

cabal new-path --dist-dir would provide the directory that used to be dist for the current target. E.g. the one that cabal new-build would build by default.

This could of course be discriminated by target.

[hvr]

How does this relate/complement/interact/differ from #2771? (or why can't the functionality be provided by e.g. show-build-info --dist-dir?)

[alexbiehl]

Check out #4220 too!

[angerman]

Wow #4220 looks pretty much like this. #2771 looks also quite usable. I just don't think that bolting the path logic into the show-build-info is a good idea, that just hides it at an obscure location. new-path is pretty self explanatory, having to go through show-build-info feels whacky to me.

However, had I known of #2771, I might now have ended up implementing cabal doctest, but turned it around and made doctest consume the show-build-info instead, which I'm coming to believe is the better solution.

[hvr]

@angerman btw, implementing cabal doctest outside of new-build (i.e. in a way that cabal would be agnostic to it) would mean that you wouldn't be able to specify additional dependencies or flags for doctest, and so cabal couldn't help you solver & install additional dependencies. So I totally think that cabal doctest is the proper way to go forward.

[fgaz]

See also #3850.

[jneira]

Last show-build-info work is in #6241, @angerman do you still think a separate command is still needed?