User private groups are not an abnormal configuration, but GHCi has such strict security that they are not allowed! :; ghci GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done.Loading package integer ... linking ... done.Loading package base ... linking ... done. *** WARNING: /Users/jsn/tmp is writable by someone else, IGNORING! *** WARNING: /Users/jsn/tmp/.ghci is writable by someone else, IGNORING! Prelude> :q Leaving GHCi. :; cd ../ :; ls -laR tmp/ tmp/: total 4 drwxrwx--- 2 jsn jsn 102 2008-12-02 10:19 . drwxr-x--- 49 jsn jsn 2890 2008-12-02 10:17 .. -rw-rw---- 1 jsn jsn 159 2008-12-02 10:20 .ghci I appreciate what you guys are trying to do, but I at the very least, it should be permitted to use a GHCi that is group readable/writable as long as the group name and user name are the same. It would be preferable, however, to do away with the restriction altogether. -- _jsn