[Bug 1843865] Re: upgrading to pre release version of Ubuntu, most likely a transient problem please try again later

[Chris Guiver]

*** This bug is a duplicate of bug 1611737 ***
    https://bugs.launchpad.net/bugs/1611737

Thank you for taking the time to report this bug and helping to make
Ubuntu better.

Ubuntu 16.04 LTS upgrade path is to 16.10 OR the next LTS, ie. 18.04
LTS.  To jump to the development release, you should start with an
updated LATEST release; you are many releases behind and not even the
latest LTS release.  A re-install is the recommended way to skip
releases.

I see lots of ROS packages in your system, this creates a known issue
and will mark this a duplicate because of that - but in your case you
should be release-upgrading to 18.04 LTS, reboot - then...


** This bug has been marked a duplicate of bug 1611737
   Can't upgrade from a release if ros packages are  installed from ROS servers

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https://bugs.launchpad.net/bugs/1843865

Title:
  upgrading to pre release version of Ubuntu,most likely a transient
  problem please try again later

Status in ubuntu-release-upgrader package in Ubuntu:
  New

Bug description:
  Calculating the changes

  Could not calculate the upgrade

  An unresolvable problem occurred while calculating the upgrade.

  If none of this applies, then please report this bug using the 
  command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal.If 
  you want to investigate this yourself the log files in 
  '/var/log/dist-upgrade' will contain details about the upgrade. 
  Specifically, look at 'main.log' and 'apt.log'. 

  
  Restoring original system state

  ProblemType: Bug
  DistroRelease: Ubuntu 16.04
  Package: ubuntu-release-upgrader-core 1:16.04.26
  ProcVersionSignature: Ubuntu 4.4.0-161.189-generic 4.4.186
  Uname: Linux 4.4.0-161-generic x86_64
  ApportVersion: 2.20.1-0ubuntu2.19
  Architecture: amd64
  CrashDB: ubuntu
  CurrentDesktop: Unity
  Date: Fri Sep 13 11:00:17 2019
  InstallationDate: Installed on 2017-12-30 (621 days ago)
  InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
  PackageArchitecture: all
  SourcePackage: ubuntu-release-upgrader
  UpgradeStatus: Upgraded to xenial on 2019-09-13 (0 days ago)

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