`cabal new-build` treats haddock failures fatally

[hvr]

originally reported at haskell-infra/hackage-trustees#146

cabal new-build currently fails when haddock fails (e.g. due to documentation: True set globally; note that Haddock currently fails for packages w/o any local modules);
instead, cabal new-build ought to merely record/log/warn about them, but otherwise carry on

[cartazio]

this seems like a high priority bug :)

where in the cabal code base is this issue? i can poke around but if theres some know how, i'd like to help get this into a point fix post haste!

[alexbiehl]

Carter, look here

cabal/cabal-install/Distribution/Client/ProjectBuilding.hs

Lines 941 to 945 in 457ebb8

	whenHaddock $ do
	when isParallelBuild $
	notice verbosity $ "Generating " ++ dispname ++ " documentation..."
	annotateFailureNoLog HaddocksFailed $
	setup haddockCommand haddockFlags

annotateFailureNoLog catches the error from Cabal and rethrows it. You probably don't want that behaviour in case of haddock.

[cartazio]

@alexbiehl ok, that helps!
better question, should we fix just that, or also not generate haddocks when theres no modules? (later seems more complicated perhaps but more correct?)

[alexbiehl]

We should do both I think:

1. Cabal shouldn't treat haddock errors as fatal errors and
2. Cabal should avoid invoking haddock if there are no inputs.

[cartazio]

@alexbiehl is your haddock work on master a fix to for master, or unrealted clean up?

should i do this patch for 2.2 or master?

[cartazio]

i'm trying to test build cabal and i'm getting this fun error

Resolving dependencies...
Configuring cabal-install-2.2.0.0...
Building cabal-install-2.2.0.0...
Installed cabal-install-2.2.0.0
Updating documentation index
/Users/carter/.cabal/share/doc/x86_64-osx-ghc-8.2.2/index.html
: cannot satisfy -package-id cabal-testsuite-2.2.0.0-inplace
(use -v for more information)

[cartazio]

this hacky first cut of a patch seems to work now that i got the build working :)

[cartazio]

the current patch just demotes haddock failures unconditionally to an adhoc warning, the right approach might be to add support for "warnings" along with full build failures.

additionally: it'd probably be good to have / retain the option to treat haddock failures as errors either per package build or globally?

additionally additionally: cabaly shouldn't even invoke haddock when theres no docs to build probably?!

[alexbiehl]

Yeah, the behaviour is yet to be specified.

For the other issue take a look here:

cabal/Cabal/Distribution/Simple/Haddock.hs

Line 111 in 335fa8d

argTargets :: [FilePath]

You might want to not invoke haddock if argTargets is empty.

[cartazio]

If you look I wrote a new function that soesnst rethrow

…

On Tue, Apr 17, 2018 at 7:45 PM Alexander Biehl ***@***.***> wrote: Yeah, the behaviour is yet to be specified. For the other issue take a look here: https://github.com/haskell/cabal/blob/335fa8d82520bad1a6980fd55230e65889c99860/Cabal/Distribution/Simple/Haddock.hs#L111 You might want to not invoke haddock if argTargets is empty. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#5232 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAQwhiQuwlx6jj8P9SYTqgidumLJneTks5tpn6ZgaJpZM4S6Uyq> .

[cartazio]

@alexbiehl thx! i'll have a look at that after i catchup with a few other things this week (my janky patch for now has me unstuck on a huge backlog at the moment :) )

Is there a mechanism in cabal at the moment for easy logging / posting of non-fatal warnings/errors to logs/user stdout/stderr? what are the current cabal-install standards for these?