Hi I'm not sure how to simplify this to a simple test case so I've put a complete tarball at http://c93.keble.ox.ac.uk/~ian/igl-0.0.4.tar.gz $ rm -f *.o *.hi Project $ HFLAGS="+RTS -K11048576 -RTS -nkpat" hmake -nhc98 Project nhc98 +RTS -K11048576 -RTS -nkpat -c -o Tokens.o Tokens.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o PCbase.o PCbase.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o PC.o PC.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Parser.o Parser.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Mangle.o Mangle.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o IA.o IA.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Offside.o Offside.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Scanner.o Scanner.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Delit.o Delit.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Args.o Args.lhs nhc98 +RTS -K11048576 -RTS -nkpat -c -o Project.o Project.lhs nhc98 +RTS -K11048576 -RTS -nkpat -o Project PCbase.o IA.o PC.o Parser.o Mangle.o Offside.o Scanner.o Tokens.o Delit.o Args.o Project.o $ cat simple.hs foo = bar $ ./Project < simple.hs Segmentation fault (core dumped) $ Thanks Ian