mplayer2 breaks release upgrade from 14.04 to 16.04

[lvm]

do-release-upgrade eventually terminates with the following error

---
Could not calculate the upgrade

An unresolvable problem occurred while calculating the upgrade.

This can be caused by:
* Upgrading to a pre-release version of Ubuntu
* Running the current pre-release version of Ubuntu
* Unofficial software packages not provided by Ubuntu
---

checking /var/log/dist-upgrade/<now>/apt.log showed that the last record starts with 'Broken mplayer2:i386 Depends on mplayer'. This is incorrect: mplayer2 does not depend on mplayer, it conflicts with mplayer. Removing mplayer2 resolved the issue. mplayer2 was installed from ubuntu repository.

Note that the original system has been successfully upgraded, apport reports come from a different system which is configured in a similar way: 14.04 and mplayer2

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-144-generic 3.13.0-144.193
ProcVersionSignature: Ubuntu 3.13.0-144.193-generic 3.13.11-ckt39
Uname: Linux 3.13.0-144-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.27
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: lvm 3080 F.... pulseaudio
 /dev/snd/controlC0: lvm 3080 F.... pulseaudio
CurrentDesktop: KDE
Date: Thu Apr 19 09:10:11 2018
GvfsMonitorLog: Monitoring events. Press Ctrl+C to quit.
HibernationDevice: RESUME=UUID=d22ce633-8298-47af-bd3b-b2f2c011e08f
HotplugNewDevices:

HotplugNewMounts:

InstallationDate: Installed on 2011-08-18 (2435 days ago)
InstallationMedia: Kubuntu 11.04 "Natty Narwhal" - Release i386 (20110427)
IwConfig:
 lo no wireless extensions.

 eth2 no wireless extensions.
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-144-generic root=UUID=b9992d14-0c4b-44a9-9946-b900b6a6eb73 ro libata.dma=5 quiet splash nomdmonddf nomdmonisw nomdmonddf nomdmonisw nomdmonddf nomdmonisw
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-144-generic N/A
 linux-backports-modules-3.13.0-144-generic N/A
 linux-firmware 1.127.24
RfKill:

SourcePackage: linux
Symptom: storage
UdevMonitorLog:
 monitor will print the received events for:
 UDEV - the event which udev sends out after rule processing
UdisksMonitorLog:
 Monitoring the udisks daemon. Press Ctrl+C to exit.
 09:10:22.820: The udisks-daemon is running (name-owner :1.27).
UpgradeStatus: Upgraded to trusty on 2014-10-18 (1279 days ago)
dmi.bios.date: 09/13/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P1.30
dmi.board.name: 990FX Extreme4
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP1.30:bd09/13/2011:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rn990FXExtreme4:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.