buildbot exception in MacPorts on ports-10.6_i386-watcher

[buildbot at macports.org]

The Buildbot has detected a build exception on builder ports-10.6_i386-watcher while building MacPorts. Full details are available at:
    https://build.macports.org/builders/ports-10.6_i386-watcher/builds/1899

Buildbot URL: https://build.macports.org/

Buildslave for this Build: ports-10.6_i386

Build Reason: A build was forced by 'ryandesign <ryandesign at localhost>': rebuild with libc++
Build Source Stamp: HEAD
Blamelist: 

BUILD FAILED: exception

Sincerely,
 -The Buildbot