Hello David. I did not build with clang, but I had similar issues. You can see yourself from the error message that the linker can't find libgfortran > ld: library not found for -lgfortran the command generated by the makefile was /usr/bin/clang -bundle -undefined dynamic_lookup -isysroot / -L/opt/local/lib build/temp.macosx-10.7-x86_64-2.7/./module/simulatormodule.o -L./libs -lsimulator -lsuperlu -llapack -lblas -ltoms -lcephes -lcalc -ldata -lgfortran -o build/lib.macosx-10.7-x86_64-2.7/simulator_.so what you want to do is find where libgfortran.a lives, in my case that's in /opt/local/lib/gcc46. You can use the command: find /opt /usr | grep libgfortran.a to find locations where it is. Pick the one that's got the same version as your compiler or you will get lots of errors about missing symbols. I think I defined an environmental variable: export LIBRARY_PATH="/opt/local/lib/gcc46/" and that was used by the make file to correctly build everything. You will of course want to put in the path to your gfortran libs in there. Good luck! ------------------------------------------------------------------ To unsubscribe from the eispice list send an email to: eispice-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field