package redmine (not installed) failed to install/upgrade: subprocess installed post-installation script returned error exit status 7

[petine]

failed to install without message.

ProblemType: Package
DistroRelease: Ubuntu 15.10
Package: redmine (not installed)
ProcVersionSignature: Ubuntu 4.2.0-32.37-generic 4.2.8-ckt4
Uname: Linux 4.2.0-32-generic i686
ApportVersion: 2.19.1-0ubuntu5
Architecture: i386
Date: Tue Mar 1 22:06:05 2016
DuplicateSignature: package:redmine:(not installed):subprocess installed post-installation script returned error exit status 7
ErrorMessage: subprocess installed post-installation script returned error exit status 7
InstallationDate: Installed on 2016-02-13 (16 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release i386 (20151021)
RelatedPackageVersions:
 dpkg 1.18.2ubuntu5.1
 apt 1.0.10.2ubuntu1
SourcePackage: redmine
Title: package redmine (not installed) failed to install/upgrade: subprocess installed post-installation script returned error exit status 7
UpgradeStatus: No upgrade log present (probably fresh install)