hi Lucas, you need to give parameters to scons when compiling on osx. i use this script: #!/bin/bash plt="/Applications/PLT Scheme v4.1/" scons -u Prefix=/opt/local/ PLTPrefix="$plt" PLTLib="$plt"/lib PLTInclude="$plt"/include sudo scons -u Prefix=/opt/local/ PLTPrefix="$plt" PLTLib="$plt"/lib PLTInclude=" $plt"/include install best, gabor