package ppp 2.4.6-3.1ubuntu1 failed to install/upgrade: subprocess new pre-installation script returned error exit status 1

[Hans-Olov Ericsson]

Crash happens at start after Upgrade from Ubuntu Gnome 14.04 to Ubuntu Gnome 15.04

lsb_release -rd
Description: Ubuntu 15.04
Release: 15.04

apt-cache policy ppp
ppp:
  Installed: 2.4.6-3.1ubuntu1
  Candidate: 2.4.6-3.1ubuntu1
  Version table:
 *** 2.4.6-3.1ubuntu1 0
        500 http://ftp.lysator.liu.se/ubuntu/ vivid/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: ppp 2.4.6-3.1ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-16.16-generic 3.19.3
Uname: Linux 3.19.0-16-generic x86_64
ApportVersion: 2.17.2-0ubuntu1
Architecture: amd64
Date: Sun May 10 11:07:33 2015
DuplicateSignature: package:ppp:2.4.6-3.1ubuntu1:subprocess new pre-installation script returned error exit status 1
ErrorMessage: subprocess new pre-installation script returned error exit status 1
InstallationDate: Installed on 2013-10-14 (572 days ago)
InstallationMedia: Ubuntu-GNOME 13.04 "Raring Ringtail" - Release amd64 (20130424)
RelatedPackageVersions:
 dpkg 1.17.25ubuntu1
 apt 1.0.9.7ubuntu4
SourcePackage: ppp
Title: package ppp 2.4.6-3.1ubuntu1 failed to install/upgrade: subprocess new pre-installation script returned error exit status 1
UpgradeStatus: Upgraded to vivid on 2015-05-10 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Shufeng (fenghhk)]

I just had the same problem when upgrading from 14.04 to 15.04.

The workaround I did was following:
1. use dpkg --ignore-depends=ppp to install packages that directly depend on ppp: network-manager, network-manager-pptp, etc.
2. edit meta info of these packages in /var/lib/dpkg/status to point to ppp 2.4.5 from 2.4.6;
3. apt-get dist-upgrade;
4. download the source code: ppp_2.4.6.orig.tar.gz
5. follow the readme to configure/make and fix the type cast error;
6. use checkinstall to create the package and dpkg install;
7. update and a patch: 2.4.6-3.1ubuntu1 to it will be applied;
8. done.