package maas-region-controller 1.7.3+bzr3363-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[James Tunnicliffe]

Performing upgrade from 14.10 to 15.04

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: maas-region-controller 1.7.3+bzr3363-0ubuntu1
ProcVersionSignature: Ubuntu 3.16.0-34.47-generic 3.16.7-ckt8
Uname: Linux 3.16.0-34-generic x86_64
ApportVersion: 2.17.2-0ubuntu1
Architecture: amd64
Date: Tue Apr 21 13:30:54 2015
DuplicateSignature: package:maas-region-controller:1.7.3+bzr3363-0ubuntu1:subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2015-02-03 (76 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.17.25ubuntu1
 apt 1.0.9.7ubuntu4
SourcePackage: maas
Title: package maas-region-controller 1.7.3+bzr3363-0ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to vivid on 2015-04-21 (0 days ago)