[Bug 2122351] Re: unshare: failed to execute /bin/true: Permission denied

[Walt Holman]

This is due to a missing file section in the /etc/apparmor.d/os-prober file. If you edit that file and find the line that looks like: 
  file /usr/bin/** ix,

and add a new line and enter the following:
  file /usr/lib/cargo/bin/coreutils/** ix,

and restart the apparmor service it should fix it. It's due to the
change to the rust version of the coreutils and the ability to swap
between rust or gnuutils. Basically the real files are located in a
subdirectory and the /usr/bin directory just contains symllinks.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to coreutils-from in Ubuntu.
https://bugs.launchpad.net/bugs/2122351

Title:
  unshare: failed to execute /bin/true: Permission denied

Status in coreutils-from package in Ubuntu:
  New

Bug description:
  Steps:

  1- I modify the grub file in the /etc/defaul/grub, the line:

  #GRUB_DISABLE_OS_PROBER=true
  GRUB_DISABLE_OS_PROBER=false

  2- Run : sudo update-grub2 and return:

  Sourcing file `/etc/default/grub'
  Sourcing file `/etc/default/grub.d/kdump-tools.cfg'
  Generating grub configuration file ...
  Found linux image: /boot/vmlinuz-6.17.0-3-generic
  Found initrd image: /boot/initrd.img-6.17.0-3-generic
  Found memtest86+ 64bit EFI image: /boot/memtest86+x64.efi
  Found memtest86+ 32bit EFI image: /boot/memtest86+ia32.efi
  Found memtest86+ 64bit image: /boot/memtest86+x64.bin
  Found memtest86+ 32bit image: /boot/memtest86+ia32.bin
  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.
  unshare: failed to execute /bin/true: Permission denied
  /usr/bin/os-prober: 25: mktemp: Permission denied
  /usr/bin/os-prober: 17: cannot create /dmraid-map: Permission denied
  /usr/bin/os-prober: 18: rm: Permission denied
  Adding boot menu entry for UEFI Firmware Settings ...
  done

  3- Check /bin/true with: ls -l /bin/true and return:

  lrwxrwxrwx 1 root root 31 Sep  4 12:07 /bin/true ->
  ../lib/cargo/bin/coreutils/true

  4- Consequence: It does not detect Windows system.

  ProblemType: Bug
  DistroRelease: Ubuntu 25.10
  Package: coreutils 9.5-1ubuntu2+0.0.0~ubuntu22
  ProcVersionSignature: Ubuntu 6.17.0-3.3-generic 6.17.0-rc3
  Uname: Linux 6.17.0-3-generic x86_64
  ApportVersion: 2.33.1-0ubuntu2
  Architecture: amd64
  CasperMD5CheckResult: pass
  CurrentDesktop: ubuntu:GNOME
  Date: Mon Sep  8 18:59:32 2025
  InstallationDate: Installed on 2025-09-01 (7 days ago)
  InstallationMedia: Ubuntu 25.10 "Questing Quokka" - Daily amd64 (20250728)
  PackageArchitecture: all
  ProcEnviron:
   LANG=es_ES.UTF-8
   PATH=(custom, no user)
   SHELL=/bin/bash
   TERM=xterm-256color
   XDG_RUNTIME_DIR=<set>
  SourcePackage: coreutils-from
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/coreutils-from/+bug/2122351/+subscriptions