Scanning binaries for linking errors when installing cairo on Mac

[hanyu-x]

Mac:~ yu$ sudo port install cairo Warning: /opt/local/etc/macports/sources.conf specifies invalid source 'rsync://rsync.macports.org/macports/release/tarballs/ports.tar [default]', ignored. Warning: System headers do not appear to be installed. Most ports should build correctly, but if you experience problems due to a port depending on system headers, please file a ticket at ​https://trac.macports.org. Warning: You can install them as part of the Xcode Command Line Tools package by running `xcode-select --install'. ---> Computing dependencies for cairo ---> Cleaning cairo ---> Scanning binaries for linking errors ---> No broken files found. ---> No broken ports found.