Some Maven-related changes when building GlassFish
By alexismp on Mar 02, 2012
The GlassFish Nexus Server (maven.glassfish.org) is put offline due to some Oracle-internal infrastructure changes.
Given that almost all GlassFish dependencies are available in Maven Central (except for EclipseLink artifacts), if you want to build GlassFish yourself, you'll need to create a mirror element in settings.xml as explained by Jane in her email.
The Build Instructions page is not up-to-date and references to maven.glassfish.org have been removed from the build setup.