WIth a coworker, I just had a problem with a fresh installation of Haskell Platform on Windows, for which we couldn't find a ready fix online. Here's what happened on how we fixed it, in hopes of helping others work around it.
regex-posix-0.94.2, which was installed as part of
haskell-platform-2010.2.0.0, had a bug in its installation script
where it didn't properly locate a dependent library (the
package) and so it would fail to link when it was loaded.
Mailing list traffic identified that this was the core problem, and it
sounded well understood, so that a fix ought to have been made,
although it wasn't obvious; I was
able to see that
regex-posix had a newer version, 0.94.4, and while
unable to find a changelog for that package, I conjectured that this
might have the fix. So I upgraded the
regex-posix package, as follows:
cabal install regex-posix-0.94.4
cabal upgrade regex-posix command might have had the same effect.
Then we had to reinstall the packages that depended on it, which we
were able to determine using the
output. In our case, the reinstall commands were as follows:
cabal install --reinstall test-framework
cabal install --reinstall test-framework-hunit
cabal install --reinstall test-framework-quickcheck2
It seems that, until we did this, these packages still depended on the old versions. Oddly, when we ran
cabal install --reinstall regex-compat, it kept its dependency on the old
regex-posix, even though
.cabal file didn't have a version limitation barring the new version. Anyone know what's up with that?
Seemingly Haskell Platform should be point-released with a dependency on the newer
regex-posix. I shall have to talk to Haskell Platform folks about whether this is the right thing.
Update Two further mailing-list posting about this: from Sept 2010 and Nov 2010.