trusty->utopic non-interactive upgrade outputs garbage, and is interactive

[Nicolas Boichat]

Updating from Trusty 14.04.

Steps to reproduce:

sudo apt-get install update-manager-core python-apt
sudo sed -i -e 's/Prompt=lts/Prompt=normal/' /etc/update-manager/release-upgrades
sudo do-release-upgrade -d -f DistUpgradeViewNonInteractive

After while, it shows text that looks like: b'\r'b'E'b'x'b't'b'r'b'a'b'c'b't'b'i'b'n'b'g'b'. You can extract some meaning out of it using sed to remove the 'b':
sed -e "s/'b'//g" upgrade.log | sed -e 's/\\r\\n/|/g' | tr '|' '\n'

And I can see that the upgrade is actually interactive:
---
Configuration file 'b"'"b'/etc/upstart-xsessions'b"'"b'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ? Your options are:
    Y or I : install the package maintainer'b"'"b's version
    N or O : keep your currently-installed version
      D : show the differences between the versions
      Z : start a shell to examine the situation
 The default action is to keep your current version.
*** upstart-xsessions (Y/I/N/O/D/Z) [default=N] ? '
---

This used to work fine (precise->trusty, saucy->trusty). Is there a new frontend that replaces DistUpgradeViewNonInteractive?

[Launchpad Janitor (janitor)]

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

[Stephen (1012web)]

The pages and pages of gibberish make it very hard to do the release upgrade with the DistUpgradeViewNonInteractive command.

[hackeron (hackeron)]

Seems like a pretty serious issue. Any solution?

[hackeron (hackeron)]

It seems this is still an issue, I am tailing apt-term.log and I see:

Configuration file '/etc/sysctl.conf'^M
 ==> Modified (by you or by a script) since installation.^M
 ==> Package distributor has shipped an updated version.^M
   What would you like to do about it ? Your options are:^M
    Y or I : install the package maintainer's version^M
    N or O : keep your currently-installed version^M
      D : show the differences between the versions^M
      Z : start a shell to examine the situation^M
 The default action is to keep your current version.^M
*** sysctl.conf (Y/I/N/O/D/Z) [default=N] ?

This should never happen as I am running: do-release-upgrade -f DistUpgradeViewNonInteractive

Any workarounds or fixes for this?

[hackeron (hackeron)]

Created a topic thread about this looking for possible workarounds: http://ubuntuforums.org/showthread.php?t=2265877

[IDHAN (j04ee9dee-d037-4748-a9c0-b6d70c12d83f)]

I can confirm this is still an issue on Xenial LTS when upgrading to Bionic LTS.
I do an 'do-release-upgrade -d -f DistUpgradeViewNonInteractive' and I'm prompted when the installation procedure comes to the user-changed etc-files. Despite entering an answer, the installation then hangs and does not proceed.