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/15173

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] 7a4cc6b94c19f3e56a168153cfaafdc4fc9b8ab5
Blamelist: Jan Starý <hans at stare.cz>

BUILD FAILED: exception

Sincerely,
 -The Buildbot