Tiago, Looking into this issue, I see from graph_tool.show_config() that openmp is not enabled on the default Macports install. So now I’m really motivated to reinstall from the latest git with openmp compilation enabled. I’m using your macports instructions <http://graph-tool.skewed.de/download> with the Portfile you provide for the latest git <http://downloads.skewed.de/graph-tool/macosx/graph-tool-devel.Portfile>, along with the Macports guide for modifying Portfiles <https://trac.macports.org/wiki/howto/Upgrade>. I’ve run into this error with the latest git build with the Portfile linked above: cd $(port dir py-graph-tool) sudo cp Portfile Portfile.orig sudo cp ~/Downloads/graph-tool-devel.Portfile.txt Portfile sudo port edit py-graph-tool sudo port -d checksum py-graph-tool sudo port -d install py-graph-tool :info:configure Command failed: cd "/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_python_py-graph-tool/py-graph-tool/work/graph-tool-devel" && ./configure --prefix=/opt/local --prefix=`python2.7-config --prefix` :info:configure Exit code: 127 :error:configure org.macports.configure for port py-graph-tool returned: configure failure: command execution failed Looking in the directory /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_python_py-graph-tool/py-graph-tool/work/graph-tool-devel, I see that there’s a file ./configure.ac, but no ./configure, so there’s some autoconf glitch. Would you please advise on building graph-tool with the Portfile graph-tool-devel.Portfile? It ow;d be great to have openmp enabled. Thanks again, Steve Could you try with the latest git version? I can't reproduce this. The script above works just fine for me. What version of graph-tool are you using?