Final bikeshedding call: Fixing Control.Exception.bracket

[Bardur Arantsson]

On 2014-11-13 04:25, Gregory Collins wrote:
> On Wed, Nov 12, 2014 at 6:37 PM, John Lato <jwlato at gmail.com> wrote:
> 
>> Do you think the current resource leaking issue is not particularly
>> significant, or do you tend to think it's an issue that should be fixed,
>> but you're weighting the unknown costs much more than I am?
> 
> 
> I'm just change averse :)
> 
> We have traditionally been very cavalier in the Haskell community about
> gratuitously changing APIs in ways that break user code, and in my opinion
> this is very bad and creates a perception for users that choosing Haskell
> is just going to end up creating work for them. In this regard I think it's
> very good to be conservative -- this function has been documented to behave
> in a certain way and you can be sure that somebody, somewhere relies on
> that behavior.
> 

I can certainly understand this perspective and *ordinarily* I'd agree
with the stance that compatibility shouldn't be broken willy-nilly.

That said, popularity isn't everything. Sometimes correctness *must*
trump the convenience of not having to change client code. And clearly
people haven't been leaving Haskell in droves on these grounds, so....

> Normally I argue strongly for this perspective (because it feels like few
> people do) on less serious things like changing function types or names,
> because those things break builds and cause people to scramble to restore
> their libraries to compatibility all at once after the GHC release. The
> consequences of *this* particular change, however, have the potential to be
> a lot worse than just making busywork for people: programs will silently
> continue to compile and then start deadlocking in mysterious (and likely
> rare/"race-condition-y") ways.
> 

... but such code is already broken in a *worse* way, namely in a
hard-to-discover and hard-to-debug way. I'll take a nearly-instantly
reproducible deadlock over a "reproducible-only-once-in-a-blue-moon"
resource leak bug any day.

This is what convinced me (and others) the last time around. What's
changed since the last time this was discussed?

Regards,