[Haskell-cafe] Re: Cabal dependency hell

[Lars Viklund]

On Thu, Mar 11, 2010 at 08:54:15AM -0800, Rogan Creswick wrote:
>  (c) fix the unpacked version, and increment the version number by
> adding a new level of detail (so, 3.1.0 becomes 3.1.0.1).  This
> version number never leaves my system -- it only exists to keep my
> cabal/ghc-pkg consistent!

A decent approach, except if the library in question is a core package
to the compiler or a library that those packages depend on.
I suffered some vast destruction doing the above to the Win32 package.
Apparently packages like directory depends on this, breaking GHC
irrecoverably if you try to propagate fixes.

I managed to limp along for a bit with constraints, but ended up wiping
the whole install and installing a clean one.