Proposal: Add exception info

[Michael Snoyman]

On Tue, Apr 21, 2015 at 5:56 PM Yitzchak Gale <gale at sefer.org> wrote:

> Michael Snoyman wrote:
> > Can you give an example of a concrete problem you're
> > expecting to run into?
>
> Package foo uploads a new version with a critical bug fix.
> As is often the case, this new version also supports updated
> dependencies, including exceptions. The new exceptions
> breaks the old SomeException type, so foo is forced to
> specify a lower bound that excludes the old exceptions.
>
>
But that's the scenario I'm asking for more information on. Can you clarify
what you're describing here? I'm not seeing a situation where an author
couldn't easily be compatible with GHC <=7.8 by sticking to the old API?


> I depend on foo and I need to compile using GHC 7.8.
> Can I get this critical bug fix for foo?
>
> We can't always prevent this kind of scenario.
> And when it does happen in an isolated case, there
> are work-arounds. But for a ubiquitous dependency
> like exceptions, this single breaking change would
> effectively block future upgrades of a significant proportion
> of Hackage for GHC 7.8.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/libraries/attachments/20150421/6a968625/attachment.html>