Simon Marlow marlowsd at
Tue Oct 23 11:25:39 CEST 2012

On 23/10/2012 09:04, Roman Leshchinskiy wrote:
> Bryan O'Sullivan wrote:
>> On Mon, Oct 22, 2012 at 4:14 PM, Simon Peyton-Jones
>> <simonpj at>wrote:
>>> Do you mean “silently and forever”?
>> I think that's what I mean, yes.
>> As Johan notes, many of us run our continuous builds of our packages with
>> -Wall -Werror in order to keep them as clean as possible. Introducing a
>> deprecation thus forces me into some kind of response as my builds all
>> suddenly fail: I can either turn off -Werror for a package, or edit the
>> affected source files.
> It seems to me that hard-coding -Werror in source distributions is a
> mistake since it serves no real purpose other than breaking the package
> for everyone whenever a compiler introduces a new warning. You can compile
> with -Werror while developing, of course. But why have -Werror in the
> release?

Quite right, shipping code with -Werror turned on is definitely a bad 
idea.  I think Hackage and/or Cabal will complain if you try to do this.


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