[Bug 2153501] Re: os-prober hangs on update-grub or kernel update

Wed May 20 23:44:33 UTC 2026

Okay, this is strange. Just for S&G, I tried again with the procedure
described in Daniel T’s answer to my question over at Ask Ubuntu:
https://askubuntu.com/a/1566464/1773099 I realized that something I’d
missed when I did this before (when the procedure failed to get os-
prober working again) was that I’d forgotten to regenerate the
bootloader. (See the three lines under “Regenerate bootloader in case
it's corrupt”.) So, I once again disabled os-prober in
/etc/default/grub, ran update-grub, reinstalled the new kernel packages,
_regenerated the bootloader,_ restarted the computer, then re-enabled
os-prober in /etc/default/grub, ran “sudo update-grub” again, and voila,
os-prober detects the Windows installation and adds it to the list,
exiting without error. So, to recap:

- When I updated to 6.17.0-23-generic, this problem occurred. It was
fixed when doing Daniel T’s procedure, including regenerating the
bootloader.

- When I updated to 6.17.0-29-generic, this problem occurred. It wasn’t
fixed when doing Daniel T’s procedure, but that might have to do with
the fact that I omitted regenerating the bootloader.

- Finally I did Daniel T’s procedure again, including regenerating the
bootloader. Now os-prober seems to work again.

So, apparently, this bug occurs _every time the kernel is updated,_ but
not every time os-prober is run. I guess we’ll see if it happens again
on the next kernel update. I’m still hoping we can fix this (it’s
annoying to have to do all that mess on every kernel update, and I’m
worried about what state the computer is left in when os-prober hangs
during a kernel update), but at least os-prober is working again for now
(fingers crossed).

Oh, and one last note: since I’m talking so much about “Daniel T’s
procedure” I should note a few things I did differently (from what he
wrote) every time I did his procedure. First, I omitted “sudo -i”,
preferring just to put “sudo” at the front of every command (I didn’t
want to risk leaving a terminal window open with root access). Second, I
didn’t bother with the “Free up space” line, instead going straight from
“sudo apt --fix-broken install” to “apt reinstall…” (etc). Finally, I
didn’t bother with the lines under “Reactivate metapackage” and “Update
to 24.04.4”; I already have the kernel metapackage linux-generic-
hwe-24.04 installed, and it turns out I was already using 24.04.4 (I had
mistakenly given him the impression that I was using 24.04.1, because of
something I saw when running “uname -r,” when I should’ve been looking
in e.g. the About screen of the Settings app). Anyway, none of this
probably matters, but because I’m being so detail-oriented with this
report I thought I should probably note all this!)

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https://bugs.launchpad.net/bugs/2153501

Title:
  os-prober hangs on update-grub or kernel update

Status in os-prober package in Ubuntu:
  New

Bug description:
  I started having this problem with the update to kernel version
  6.17.0-23-generic. What happened is described here:
  https://askubuntu.com/questions/1566462/software-updater-has-hung-
  while-configuring-a-kernel-update-what-do-i-do The short version is
  that, while configuring linux-image-6.17.0-23-generic, it would look
  for the different installed kernels and then run os-prober to detect
  any other OSes, and os-prober, presumably while attempting to do this,
  would hang. The solution, it turned out, was to kill the dpkg process,
  disable os-prober manually in /etc/default/grub, use “sudo dpkg
  --configure -a” and “sudo apt --fix-broken install”, then reinstall
  the new kernel packages (just in case something went wrong when
  killing dpkg), restart, re-enable os-prober manually in
  /etc/default/grub, run “sudo update-grub”, and watch as it would run
  os-prober, which then ran with no hangs. Success! (Note that before I
  did any of this, os-prober was neither explicitly enabled nor
  explicitly disabled; I’ve read that os-prober is disabled by default
  these days, but it wasn’t disabled for me, it simply hung when it was
  ran.) I restarted my computer and indeed, the bootloader gave me the
  option of booting into my other OS (Windows 11), though of course I
  kept on using Ubuntu.

  So, this morning, it came time to install the new kernel packages for
  kernel version 6.17.0-29-generic. I told Software Updater to install
  the updates, and… the same thing happened as before, where, when
  configuring the new kernel image package, it attempted to run os-
  prober, and os-prober would hang. So, I followed the same steps as
  last time (except of course, I made sure to change "6.17.0-23-generic”
  to “6.17.0-29-generic” when re-entering the command to reinstall the
  new kernel packages), but now, os-prober still hangs whenever it’s
  called, even though I’ve disabled it, restarted, and re-enabled it.
  Whether I’m running the command to reinstall the new kernel packages,
  or running “sudo update-grub” manually, it always hangs when calling
  os-prober. The only solution for me, right now, is to disable os-
  prober manually in /etc/default/grub, which is obviously not ideal for
  a dual-boot system!

  So, yeah, something is going wrong with os-prober and I’m not sure
  what. To make it clear: the expected behavior was for os-prober to
  detect the other OS on the system (Windows 11) and finish and for that
  other OS to be added to the grub boot menu, but what happens instead
  is that os-prober hangs indefinitely (at the message “Warning: os-
  prober will be executed to detect other bootable partitions. Its
  output will be used to detect bootable binaries on them and create new
  boot entries.”). Let me know what I can do to help fix this; I’d also
  like to know if there are any good workarounds to make sure the
  Windows partition is bootable in the meantime.

  I’m using Ubuntu 24.04.4 LTS on a ThinkPad P53. The installed os-
  prober package is version 1.81ubuntu4.

  ProblemType: Bug
  DistroRelease: Ubuntu 24.04
  Package: os-prober 1.81ubuntu4
  ProcVersionSignature: Ubuntu 6.17.0-29.29~24.04.1-generic 6.17.13
  Uname: Linux 6.17.0-29-generic x86_64
  NonfreeKernelModules: nvidia_modeset nvidia
  ApportVersion: 2.28.1-0ubuntu3.8
  Architecture: amd64
  CasperMD5CheckResult: pass
  CurrentDesktop: ubuntu:GNOME
  Date: Wed May 20 14:32:39 2026
  InstallationDate: Installed on 2024-12-08 (529 days ago)
  InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64 (20240827.1)
  RebootRequiredPkgs: Error: path contained symlinks.
  SourcePackage: os-prober
  UpgradeStatus: No upgrade log present (probably fresh install)

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