Breakage with ghc-6.10

Duncan Coutts duncan.coutts at
Fri Oct 10 14:41:06 EDT 2008

Sorry Ashley, I hope you didn't feel I was picking on you in particular.
I realise it might have looked that way.

On Fri, 2008-10-10 at 11:08 -0700, Ashley Yakeley wrote:
> On Fri, 2008-10-10 at 09:08 -0700, Duncan Coutts wrote:
> > Failing due to -Werror.
> > 
> > NOOOOooooooooooooooooooo!!!!!!
> > 
> > This is the reason that hackage now rejects the use of -Werror in
> > released packages. It causes unnecessary breakage when new compilers
> > add new warnings.
> Warnings in a build process should be fixed, not ignored (and, I would
> say, fixed by whoever introduced the warning or otherwise broke the
> build).

Yes indeed.

So it's appropriate for development builds.

> Hackage, on the other hand, is right to reject -Werror in .cabal files,
> as there the build is really part of the install process and should be
> as lenient as possible. I pass --ghc-options="-Wall -Werror" to cabal in
> a Makefile in most of my projects, so that my development build process
> is strict.

Right. Putting -Wall in the ghc-options in the .cabal file is fine too
of course. Lots of packages do that.


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