Hi! (please CC me as I am not subscribed) Happens on Cabal darcs head and Windows with ghc. In Distribution.Simple.GHC.build we try to invoke ld. In Windows this file is found by deduction from ghc.exe path. (foo\bin\ghc.exe -> foo\gcc-lib\ld.exe). When this absolute (rooted) path is passed on to rawSystem*, it gets search through PATH environment-variable in System.Directory.findExecutable (or the version in Compat.) System.Directory.findExecutable went through a rewrite for Windows between 6.4 series and 6.5 - it now uses Windows API function SearcPath which passes absolute paths straight throuhg, at least on my system (Windows XP). In the end, because 6.4.2 doesn't let absolute paths through, we need a fix. What is the right way here? Assume ghc 6.4.3 and get fix merged (see diff [1]); Add extra check for absolute path and file existence on findExecutable (and propagate this fix to base); Or inline the rawSystem* (as needed) in GHC.hs under correct preprocessor if's? Oh, yeah, we can also say that ghci libs just don't work under 6.4.x in Windows ;) Please advice. [1] http://cvs.haskell.org/cgi-bin/cvsweb.cgi/fptools/libraries/base/System/Directory.hs.diff?r1=text&tr1=1.49.2.5&r2=text&tr2=1.59 Best regards, --Esa