The admin directory is just for the GMT developers to store configuration files and scripts useful for building the actual releases.
In addition to the packages required for building all of GMT (including documentation), you also need gnu-tar and coreutils.
- build-release.sh
- build-macos-external-list.sh
- ConfigReleaseBuild.cmake
Make sure you are in the top gmt directory and then run
admin/build-release.sh [-help]
to see the various options available.