I have no idea. Ian may be able to help. Ian, or anyone else... any ideas? I would start with ghc-pkg list and ghc-pkg check Simon From: Ilya Sergey [mailto:ilya.sergey@imdea.org] Sent: 21 March 2013 01:25 To: Simon Peyton-Jones Subject: default library path in HEAD Hi Simon. I've run into some troubles trying to build the nofib with the current master branch. Apparently, something has changed in the default library path, so the stage2 compiler cannot find base modules: ~~~~~~~~~~~ /Users/ilya/repos/master-ghc/inplace/bin/ghc-stage2 -H64m -O -fasm -O -Rghc-timing -package array -H32m -hisuf hi -rtsopts -c Main.hs -o Main.o Main.hs:1:1: Failed to load interface for ‛Prelude’ There are files missing in the ‛base’ package, try running 'ghc-pkg check'. Use -v to see a list of the files searched for. ~~~~~~~~~~~~ The library has been compiled with profiling options (added to the end of build.mkhttp://build.mk): GhcLibHcOpts += -ticky GhcRTSWays += t GhcThreaded = NO and BuildFlavour = devel2 But I don't think it is an issue. What am I doing wrong? Thanks. Ilya