GHC 6.12 + zlib + Mac OS 10.6

Antoine Latter aslatter at
Sat Nov 28 16:01:26 EST 2009

Hello folks,

Everything has been going beautifully with the latest versions of GHC
6.12, except that anything involving zlib dies at run-time. In ghci:

> :m Codec.Compression.Zlib
> :m +Data.ByteString.Lazy.Char8
> :s -XOverloadedStrings
> compress "hello"

*** Exception: user error (Codec.Compression.Zlib: incompatible zlib version)

I'm running OS X 10.6 on a 64-bit machine.

I've heard of folks running into this with GHC 6.10 on OS X 10.6, who
got rid of it by removing mac-ports. I tried that and it didn't change
anything. My mac-ports install should have all been universal binaries

I imagine I'm somehow building against a 64-bit version of the zlib
library, but I'm not sure at what step I'm supposed to do things
different, or what precisely I'm supposed to do different.


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