No terminal, and no DISPLAY set, can't fork shell.

[Scott Moser]

Binary package hint: update-manager

I'm testing do-release-upgrade on ec2 from maverick -> natty
I'm doing so by:
 - ssh in
 - byobu
 - sudo apt-get update && sudo apt-get dist-upgrade
 - sudo do-release-upgrade -d

At a point during the upgrade it tells me that /etc/default/grub has been
locally modified. One of the options in this dialog is to:
  "start a new shell to examine the situation"

When I select that option, I see:
  No terminal, and no DISPLAY set, can't fork shell.

I'm not certain that this is update-manager related, but I dont' recall having seen it before.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: update-manager-core 1:0.150
ProcVersionSignature: User Name 2.6.35-24.42-virtual 2.6.35.8
Uname: Linux 2.6.35-24-virtual i686
Architecture: i386
Date: Thu Apr 21 21:23:56 2011
Ec2AMI: ami-a6f504cf
Ec2AMIManifest: ubuntu-images-us/ubuntu-maverick-10.10-i386-server-20101225.manifest.xml
Ec2AvailabilityZone: us-east-1c
Ec2InstanceType: m1.small
Ec2Kernel: aki-407d9529
Ec2Ramdisk: unavailable
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: Upgraded to natty on 2011-04-21 (0 days ago)

[RedSingularity (redsingularity)]

Are you still seeing this error with the most recent updates?

[Scott Moser (smoser)]

@RedSingularity,
  Why would i *not* be seeing this on the most recent updates. The most recent update-manager package in the archive is the same version that this bug was reported against. (Package: update-manager-core 1:0.150)
  Please do not simply ask a question and mark bugs as incomplete. Have some justification for why you're asking.

[Scott Moser (smoser)]

Hm.. I just re-read that, and I apologize for the tone.

Do you have a reason to believe that this bug is fixed ?

[RedSingularity (redsingularity)]

Many times I have seen that another packages updates 'fix' problems in the update-manager. I was just wondering since its been a few days since you filed. I am going to try this out on my test machine.

I assume I will have to edit the grub file before running one of the commands above to get the error you are talking about. Let you know what happened ASAP :)

[RedSingularity (redsingularity)]

Ok, just finished testing it. I got the prompt you were referring too, and chose "start a new shell to examine the situation". It seemed to work fine here. Brought up a new terminal window logged in as root under the root directory. Tested on an upgrade from maverick to natty.

[Jakob Bohm (jb-debbugs)]

This is actually a bug in package ucf, identical to Debian bug 574266 (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=574266#18), which was recently fixed with a one-line patch.

The code that tested for terminal availability would fail if the debconf ncurses interface (whiptail) was used, and the program was /not/ run under X. So when upgrading from the console or via ssh (without the -x option), it would always generate this error message,

For additional details, see the Debian bug report, which includes a patch.

[Steve Langasek (vorlon)]

ok, so based on this information about it being a ucf bug (confirmed, the error message in the ucf bug report is the same as the one here), this is fixed in Ubuntu 13.10 and later - though not, unfortunately, in 12.04.

If we continue to see reports of this problem on upgrades from 12.04 to 14.04, we can consider an SRU of ucf to 12.04 to mitigate.