On Tue, Jun 02, 2009 at 10:26:34AM +0100, Duncan Coutts wrote:
>

> You mentioned in the ticket that we need to have base strictly following
> the PVP. That's true of course. I'm assured by the GHC hackers that
> they're committed to the PVP. The reason for bumping 4.0 -> 4.1 is being
> looked at but their first guess is that it was the change in GHC's
> finaliser semantics (which did indeed break a couple programs).

The reason base's version was bumped from 4.0 to 4.1 is that there were
some changes that required it, according to the PvP, e.g.
   GHC.Conc.signalHandlerLock
was removed.

I don't know if there were any such changes in non-GHC.* modules, as I
stopped looking when I found the first change.

For the future, one option would be to exclude GHC.* from the PvP
requirements, although then you have problems with any package which
uses GHC.*.