Netboot Loading libc6-udeb failed for unknown reasons (focal) 2020-04-21

[papamoose]

With the netboot image from 2020-04-21 (http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/current/legacy-images/netboot/) it shows me following error at partition disk space step

          ???????????????????? [!!] Detect disks ?????????????????????
          ? ?
          ? Failed to load installer component ?
          ? Loading libc6-udeb failed for unknown reasons. Aborting. ?
          ? ?
          ? <Go Back> <Continue> ?
          ? ?
          ????????????????????????????????????????????????????????????

I am unable to preseed install via PXE because of this.

This bug seems to be identical to previous reports which got fixed in the past.
https://bugs.launchpad.net/ubuntu/+source/debian-installer/+bug/1867502

[papamoose (papam0ose)]

While the bug seems to be identical to 1867502, because it was fixed (2020-03-17) and working for a whole year and now (2021-04-21) broke with the release of a new netboot image I would consider this a new bug. The fix may be the same.

[Chris Guiver (guiverc)]

A known & trusted user reported the other bug fixed on 2020-03-18, but the bug did not reach CONFIRMED status until 2020-03-20 (two days after the 'fixed' report).

The other bug is still OPEN & has a CONFIRMED status.

This bug report has yet to be confirmed, so I'll treat it as unique.

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When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.

[Marcel (mkcionix)]

I can confirm this bug. It bricked yesterday, right after the changes to the libc6-udeb package
https://launchpad.net/ubuntu/focal/amd64/libc6-udeb.

[Launchpad Janitor (janitor)]

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

[Steven Clarkson (sclarkson)]

This is caused by the libc update done in LP: #1914044

My workaround is to put this line in my early_command

sed -i -e '/Package: libc6-udeb/{N;N;s/Version: 2.31-0ubuntu9.*/Version: 2.31-0ubuntu9.3/}' /var/lib/dpkg/status

[papamoose (papam0ose)]

@sclarkson: I can confirm that your early command does work around the problem:

`d-i preseed/early_command string \
  sed -i -e '/Package: libc6-udeb/{N;N;s/Version: 2.31-0ubuntu9.*/Version: 2.31-0ubuntu9.3/}' /var/lib/dpkg/status`

@guiverc: Unfortunately tty 2 and 3 won't load to run the command.
'-/bin/sh: error while loading shared libraries: __vdso_gettimeofday: invalid mode for dlopen(): Invalid argument'

Steven Clarkson wrote verified this outside the debian-installer as well: https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1914044/comments/16

[Jakuro (jakuro)]

@sclarkson: Can you explain how this fix works? As it doesn't work for me. For me there is error in retrieving version 2.31-0ubuntu9.3 and your sed is changing 9>* to 9.3.

[Brandon Wade (brandonwade)]

I can also confirm this bug. I can also confirm that the workaround proposed by @sclarkson is not working for our environment either. This bug is preventing our organization from installing unattended via PXE. A more bulletproof workaround or fix is most desired.

[Brandon Wade (brandonwade)]

EDIT: After further troubleshooting, and finding a typo in the preseed file, I can also confirm that the workaround proposed by @sclarkson is working successfully by allowing the installation to complete without error.

[Steven Clarkson (sclarkson)]

@Jakuro: This just tricks udpkg in the install environment into thinking that it is already at 2.31-0ubuntu9.3 so it doesn't try to update, and therefore doesn't fail. It's is 9.* to catch 9 in the focal installer and 9.2 in the focal-updates installer.

A simpler sed is probably sufficient, and less prone to typos. This one is untested, though.

sed -i -e 's/Version: 2.31-0ubuntu9.*/Version: 2.31-0ubuntu9.3/' /var/lib/dpkg/status

[papamoose (papam0ose)]

Not sure if this is correct for this case but it looks like in the past an updated netboot image was provided which listed the updated version of libc6-udeb.

diff ubuntu/dists/focal/main/installer-amd64/current/legacy-images/udeb.list ubuntu/dists/focal-updates/main/installer-amd64/current/legacy-images/udeb.list |grep libc6-udeb
< libc6-udeb 2.31-0ubuntu9 amd64
> libc6-udeb 2.31-0ubuntu9.2 amd64

[Balint Reczey (rbalint)]

Thanks for the bug report. The glibc update has been moved back to focal-proposed thus the netboot image should work again.

[Launchpad Janitor (janitor)]

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

[papamoose (papam0ose)]

I can confirm that preseeding works now without @sclarkson's workaround.