[#5503] Add filterHaddockFlags for new-haddock

[chshersh]

---

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I've tried to add additional logic suggested by the issue. But I still see the error:

Build profile: -w ghc-8.4.3 -O1
In order, the following will be built (use -v for more details):
 - network-2.7.0.2 (first run)
cabal: Unrecognised flags: lib:network
Warning: Failed to build documentation for network-2.7.0.2.

[alexbiehl]

Great! Thanks @chshersh! And sorry for the oversight!

[hvr]

@alexbiehl the problem appears to be (haven't investigated enough to be sure) that build-type:configure throws the package into legacy mode and thus disables per-component -- this appears to disable support for passing arguments such as lib:network to Setup.hs haddock

@chshersh I'm afraid, we need to do a bit more here; we need to e.g. extend the arg filtering to detect this case somehow

[hvr]

@alexbiehl @chshersh take a look at this here

cabal/Cabal/Distribution/Simple.hs

Line 708 in 0c97920

noExtraFlags a

(IOW, this was an oversight of #5226)

I'm afraid we've been looking at the wrong place to fix this...

[hvr]

different fix needed:

• try using readHookWithArgs for preHaddock
• (maybe) write a regression test-case

@chshersh maybe open a separate PR; I'd like to leave this PR open as it may still have merit on its own for consistency reasons

[chshersh]

@hvr Sure, no problems. I will do the work in separate PR 👌

[hvr]

As discussed w/ @chshersh and due to the urgency involved I've created #5573 myself

[chshersh]

@hvr @23Skidoo Could you, please, provide some updates on what is required for this PR to be done? Am I right that this is resolved in #5573 or is something needs to be done here as well?