Hello everyone I tried installing yt on my mac (os X 10.6.8) today and I had a failure. The last lines in the log file are: gcc-4.2 -bundle -undefined dynamic_lookup -L/Applications/yt-i386/lib/ -L/Applications/yt-i386/lib64/ -L/Applications/yt-i386/lib/ -L/Applications/yt-i386/lib64/ -L/Applications/yt-i386/lib/ -L/Applications/yt-i386/lib64/ -L/Applications/yt-i386/lib/ -L/Applications/yt-i386/lib64/ -arch x86_64 build/temp.macosx-10.4-x86_64-2.7/fKDpymodule.o build/temp.macosx-10.4-x86_64-2.7/Forthon.o build/temp.macosx-10.4-x86_64-2.7/fKD.o build/temp.macosx-10.4-x86_64-2.7/fKD_p.o build/temp.macosx-10.4-x86_64-2.7/fKD_source.o -L/usr/local/gfortran/lib/gcc/x86_64-apple-darwin10/4.6.2 -lgfortran -o ./fKDpy.so -flat_namespace ld: warning: directory '/Applications/yt-i386/lib64/' following -L not found ld: warning: directory '/Applications/yt-i386/lib64/' following -L not found ld: warning: directory '/Applications/yt-i386/lib64/' following -L not found ld: warning: directory '/Applications/yt-i386/lib64/' following -L not found Cython is a build-time requirement for the source tree of yt. Please either install yt from a provided, release tarball, or install Cython (version 0.16 or higher). You may be able to accomplish this by typing: pip install -U Cython I have cython 0.17 installed on my machine but I'm not sure why it does not recognize it. Any suggestions? Best Ricardo