http://www.google.com/search?hl=en&q=fedora+haskell+libreadline.so.4&btnG=Search&meta= gives: http://www.nabble.com/-Haskell--Re:-kernel-2.6.11-and-readline.so-t577156.ht... as the first result, which appears to give a solution.... and, in fact, if I look at: http://haskell.org/ghc/download_ghc_661.html which is where I presume you got the rpm from it states that: "Note: You need the libreadline.so.4 and libncurses.so.5 libraries to use this. Newer Linux distributions come with libreadline.so.5 only (e.g. SuSE 9.2), so we have provided a readline4 compatiblity RPM for this case." I've got a sneaking suspicion that the 'readline4 compatibility RPM' linked to would solve your problem. Or maybe the fedora package manager chases dependencies?