buildbot exception in MacPorts on ports-10.13_x86_64-builder

[buildbot at macports.org]

The Buildbot has detected a build exception on builder ports-10.13_x86_64-builder while building macports/macports-ports. Full details are available at:
    https://build.macports.org/builders/ports-10.13_x86_64-builder/builds/16879

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

Buildslave for this Build: ports-10.13_x86_64

Build Reason: The Triggerable scheduler named 'ports-10.13_x86_64-trigger' triggered this build
Build Source Stamp: [branch master] d825a43ff1a03a030ea73a08155618e390aab6f7
Blamelist: Eric A. Borisch <eborisch at macports.org>

BUILD FAILED: exception install-dependencies cleanup

Sincerely,
 -The Buildbot