I couldn't seem to logon to the trac to report this. I'm working on windows (not linux as the chmod might suggest). zlib-0.5.0.0>runghc Setup.hs configure --package-db=..\..\ghc\ghc-6.10.1\fpf.package.conf --docdir=..\..\haskell_packages\doc\zlib-0.5.0.0 --libdir=..\..\haskell_packages --bindir=..\..\haskell_packages\bin Configuring zlib-0.5.0.0... zlib-0.5.0.0>runghc Setup.hs build Preprocessing library zlib-0.5.0.0... Building zlib-0.5.0.0... ghc-6.10.1\bin\ar.exe: creating dist\build\libHSzlib-0.5.0.0.a zlib-0.5.0.0>runghc Setup.hs install Setup.hs: ..\..\haskell_packages\doc\zlib-0.5.0.0\.copyFile920.tmp: copyFile: permission denied (Access is denied.) Cabal seesm to create certain things as read only. I can work around this by chmod a+w ..\ThirdParty\haskell_packages\zlib-0.5.0.0\ghc-6.10.1\include\* chmod a+w ..\ThirdParty\haskell_packages\doc\zlib-0.5.0.0\* rm ..\ThirdParty\haskell_packages\doc\zlib-0.5.0.0\* I suspect most people haven't tripped over this as once something is installed they don't tend to install it again. Dominic.