locale.Error: unsupported locale setting

[Teluka]

OS: Ubuntu 20.04.6 LTS
Landscape client: 23.02-0ubuntu1

Due to missing locale, the landscape client couldn't report the list of installed packages to the landscape server (SAAS).

2023-05-10 17:23:10,675 WARNING [MainThread] Package reporter output:
b'Traceback (most recent call last):
  File "/usr/bin/landscape-package-reporter", line 10, in <module>
    main(sys.argv[1:])
  File "/usr/lib/python3/dist-packages/landscape/client/package/reporter.py", line 872, in main
    locale.setlocale(locale.LC_CTYPE, ("C", "UTF-8"))
  File "/usr/lib/python3.8/locale.py", line 608, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
'

As a result, the server kept reporting available updates for the machine and when the update was triggered it failed with the following error reported in the task activity.

"Package data has changed. Please retry the operation."

For example on the affected client machine the "apt list --installed | grep dnsmasq-base" gives the output
"dnsmasq-base/focal-updates,focal-security,now 2.80-1.1ubuntu1.7 amd64

However, landscape server keeps reporting that update (2.80-1.1ubuntu1.7) is available.

[Juanmi Taboada (juanmitaboada)]

I think the client machine should address this bug. A hint to resolve it could be:
sudo locale-gen en_US.UTF-8
sudo update-locale LANG=C.UTF-8

Landscape Client could also try to prevent future failures when detected by applying the solution proposed above:

@@ -3,6 +3,7 @@
 except ImportError:
     import urllib.parse as urlparse

+import subprocess
 import locale
 import logging
 import time
@@ -943,7 +944,12 @@
 def main(args):
     # Force UTF-8 encoding only for the reporter, thus allowing libapt-pkg to
     # return unmangled descriptions.
- locale.setlocale(locale.LC_CTYPE, ("C", "UTF-8"))
+ try:
+ locale.setlocale(locale.LC_CTYPE, ("C", "UTF-8"))
+ except locale.Error:
+ subprocess.run(["sudo", "locale-gen", "en_US.UTF-8"], check=True)
+ subprocess.run(["sudo", "update-locale", "LANG=C.UTF-8"], check=True)
+ raise

     if "FAKE_GLOBAL_PACKAGE_STORE" in os.environ:
         return run_task_handler(FakeGlobalReporter, args)

There is a PR with this proposed solution at:
https://github.com/CanonicalLtd/landscape-client/pull/161

[Juanmi Taboada (juanmitaboada)]

I will go with Mitch's suggestion to address this issue through the postinst script during package installation.

[Michael Atkins (neroprotagonist)]

I had the same error on one client machine and not another one even though both machines had LANG=en_GB.UTF-8 in /etc/default/locale and ran identical python version 3.8.10.

After some debugging using strace I found that the solution was to install/configure the en_US.UTF-8 locale using
dpkg-reconfigure locales
and making sure the en_US.UTF-8 was selected.

Also, I don't think a fix should alter the locale on a client machine (i.e. using update-locale) given that the whole point in locales is to support different regions and you would prevent the client from achieving this.