id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,port 59404,boost fails to build on Mac OS X Lion,RobK88,michaelld,"I am unable to build boost on my old Mac running Lion. Macports is configured to use libc++. {{{ ---> Computing dependencies for boost ---> Configuring boost ---> Building boost Error: Failed to build boost: command execution failed Error: See /opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_devel_boost/boost/main.log for details. Error: rev-upgrade failed: Error rebuilding boost Error: Follow https://guide.macports.org/#project.tickets to report a bug. }}} I have also tried to upgrade boost using the following commands without success: {{{ sudo port clean boost sudo port upgrade boost configure.compiler=clang }}} I finally ran the following upgrade command with the verbose option: sudo port -v upgrade boost Attached please find the output of the command. I also have attached the main.log file. P.S. As recommended, I have removed the default.compilers line from macports.conf for Macports 2.6.x ",defect,closed,Normal,,ports,2.6.1,duplicate,lion,ryandesign,boost