buildbot exception in MacPorts on ports-10.6_i386_legacy-watcher

[buildbot at macports.org]

The Buildbot has detected a build exception on builder ports-10.6_i386_legacy-watcher while building macports/macports-ports. Full details are available at:
    https://build.macports.org/builders/ports-10.6_i386_legacy-watcher/builds/16875

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

Buildslave for this Build: ports-10.6_i386_legacy

Build Reason: The SingleBranchScheduler scheduler named 'ports' triggered this build
Build Source Stamp: [branch master] 7bf5a7543ba82177d4278e8d698c68c5d12c4ca8
Blamelist: David B. Evans <devans at macports.org>

BUILD FAILED: exception

Sincerely,
 -The Buildbot