Muon Distribution Upgrade Freezes on DPkg Input

During upgrade from 15.04 to 15.10, muon froze when configuring salt-minion. I later discovered that salt-minion had a configuration file change and required input from the user as to whether to keep the existing config or replace it with the new upstream configuration. I suspect the request for user input may have frozen the upgrader.

Note that Muon was completely frozen, so I was unable to send a bug report from the menu. This report is from the command line.

lsb_release -rd:
Description: Ubuntu 15.10
Release: 15.10

muon-updater:
  Installed: 4:5.4.2-0ubuntu1
  Candidate: 4:5.4.2-0ubuntu1
  Version table:
 *** 4:5.4.2-0ubuntu1 0
        500 http://ca.archive.ubuntu.com/ubuntu/ wily/universe amd64 Packages
        100 /var/lib/dpkg/status

Reproduction Steps:

1. Install and configure salt-minion on Kubuntu 15.04
2. Upgrade to Kubuntu 15.10 through muon

Expected behavior:

Muon completes in a few hours with a minimum of drama

Observed Behavior:

Muon upgrader frozen overnight, stuck on configuring salt-minion.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: muon-updater 4:5.4.2-0ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-18.22-generic 4.2.3
Uname: Linux 4.2.0-18-generic x86_64
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CurrentDesktop: KDE
Date: Tue Nov 17 14:29:37 2015
InstallationDate: Installed on 2014-09-18 (425 days ago)
InstallationMedia: Kubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2)
SourcePackage: muon
UpgradeStatus: Upgraded to wily on 2015-11-17 (0 days ago)