lxc-attach command does not return error exit code if the command is failed

[EOLE team]

lxc-attach command does not return error exit code if the command is failed on Ubuntu Focal :

root@scribe:~# lxc-start --version
3.0.4
root@scribe:~# lxc-attach --logpriority=DEBUG --name=addc -- exit
lxc-attach: addc: attach.c: lxc_attach_run_command: 1489 No such file or directory - Failed to exec "exit"
root@scribe:~# echo $?
0

The problem is fixed upstream : https://github.com/lxc/lxc/issues/3104 and by Debian : https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=934983

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: lxc-utils 3.0.4-0ubuntu2
ProcVersionSignature: Ubuntu 5.4.0-12.15-generic 5.4.8
Uname: Linux 5.4.0-12-generic x86_64
ApportVersion: 2.20.11-0ubuntu16
Architecture: amd64
Date: Tue Feb 4 16:01:30 2020
InstallationDate: Installed on 2020-01-10 (25 days ago)
InstallationMedia: Ubuntu-Server 20.04 LTS "Focal Fossa" - Alpha amd64 (20200105)
SourcePackage: lxc
UpgradeStatus: No upgrade log present (probably fresh install)
defaults.conf:
 lxc.net.0.type = veth
 lxc.net.0.link = lxcbr0
 lxc.net.0.flags = up
 lxc.net.0.hwaddr = 00:16:3e:xx:xx:xx
lxc-net.default:
 USE_LXC_BRIDGE="true"
 LXC_BRIDGE="br0"
 LXC_ADDR="192.0.2.1"
 LXC_NETMASK="255.255.255.0"
 LXC_NETWORK="192.0.2.0/24"

[Launchpad Janitor (janitor)]

This bug was fixed in the package lxc - 1:4.0.0-0ubuntu2

---------------
lxc (1:4.0.0-0ubuntu2) focal; urgency=medium

  * Cherry-pick upstream bugfixes:
    - 0036-fix-non-root-user-cannot-write-dev-stdout.patch
    - 0037-cgroups-fix-uninitialized-transient_len-warning.patch
    - 0038-utils-rework-fix_stdio_permissions.patch
    - 0039-utils-use-setres-u-g-id-in-lxc_switch_uid_gid.patch
    - 0040-cgroups-fix-build-warning-on-GCC-7.patch
    - 0041-lxccontainer-poll-takes-millisecond-not-seconds.patch

 -- Stéphane Graber <email address hidden> Thu, 02 Apr 2020 12:25:20 -0400

[EOLE team (eole-team)]

OK for us with 1:4.0.1-0ubuntu2 package on focal :

root@scribe:~# lxc-start --version
4.0.1
root@scribe:~# lxc-attach --logpriority=DEBUG --name=addc -- exit
lxc-attach: addc: attach.c: lxc_attach_run_command: 1452 No such file or directory - Failed to exec "exit"
root@scribe:~# echo $?
127