scp-dbus-service.py crashed with Error in setlocale(): unsupported locale setting

[Gorfou]

Binary package hint: system-config-printer

Having installed the multipurpose printer hp, I wanted to print a page of test and right away I had error.
The page of test did not work.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: system-config-printer-common 1.3.1+20110222-0ubuntu12
ProcVersionSignature: Ubuntu 2.6.38-7.39-generic 2.6.38
Uname: Linux 2.6.38-7-generic x86_64
Architecture: amd64
Date: Sun Apr 3 11:46:08 2011
ExecutablePath: /usr/share/system-config-printer/scp-dbus-service.py
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Beta amd64 (20110330)
InterpreterPath: /usr/bin/python2.7
Lpstat: device for HP-Photosmart-2570-series: hp:/net/Photosmart_2570_series?zc=HPB49503
MachineType: Gigabyte Technology Co., Ltd. GA-MA790X-UD3P
Papersize: letter
PpdFiles: HP-Photosmart-2570-series: HP Photosmart 2570 Series, hpcups 3.11.1
ProcCmdline: /usr/bin/python /usr/share/system-config-printer/scp-dbus-service.py
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=fr_FR.UTF-8
 LC_MESSAGES=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-7-generic root=UUID=9001715d-0dbe-43b9-b47c-31470e787770 ro quiet splash vt.handoff=7
PythonArgs: ['/usr/share/system-config-printer/scp-dbus-service.py']
SourcePackage: system-config-printer
Title: scp-dbus-service.py crashed with Error in setlocale(): unsupported locale setting
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
dmi.bios.date: 04/02/2010
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F7a
dmi.board.name: GA-MA790X-UD3P
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF7a:bd04/02/2010:svnGigabyteTechnologyCo.,Ltd.:pnGA-MA790X-UD3P:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnGA-MA790X-UD3P:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: GA-MA790X-UD3P
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

[Till Kamppeter (till-kamppeter)]

Looks like the applet does not work with any non-English locale. Tim, can you have a look into this?

[Tim Waugh (twaugh)]

Works here.

[Till Kamppeter (till-kamppeter)]

For me it looks like this is a problem of Python. I can reproduce the error by directly calling Python:

till@till:~$ LC_ALL=C python -c 'import locale; print locale.setlocale (locale.LC_ALL, "")'
C
till@till:~$ LC_ALL=en_US.UTF-8 python -c 'import locale; print locale.setlocale (locale.LC_ALL, "")'
en_US.UTF-8
till@till:~$ LC_ALL=de_DE.UTF-8 python -c 'import locale; print locale.setlocale (locale.LC_ALL, "")'
de_DE.UTF-8
till@till:~$ LC_ALL=en_US python -c 'import locale; print locale.setlocale (locale.LC_ALL, "")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python2.7/locale.py", line 531, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
till@till:~$ LC_ALL=de_DE python -c 'import locale; print locale.setlocale (locale.LC_ALL, "")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/python2.7/locale.py", line 531, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
till@till:~$

This means that Python accepts locales with "UTF-8" specification but not without.

I am not a locale expert so I do not know what really needs to get fixed in Python or in Ubuntu's locales, but a workaround in system-config-printer by surrounding locale.setlocale() with "try: ... except: ..." could solve the problem. Tim, WDYT?

[Till Kamppeter (till-kamppeter)]

The attached patch fixes the problem. It simply surrounds the crashing locale.setlocale() call with "try: ... except: pass". TIM, WDYT? Is this correct? What is the locale.setlocale() call good for? The returned result is not used.

[Till Kamppeter (till-kamppeter)]

To all users who reported this bug and its duplicates, you can test by applying the patch of comment #5 via the following commands in a terminal window.

cd /
sudo patch -p0 < scp-dbus-service-py-do-not-fail-on-bad-locale.patch

After that close all system-config-printer windows and start system-config-printer again. Does it work now?

[Tim Waugh (twaugh)]

I can apply that, sure. It's pretty silly that setlocale can fail though IMHO.

Till: setlocale is for initialising e.g. gettext().

[Till Kamppeter (till-kamppeter)]

Tim applied the patch upstream as GIT rev 6b105d3. Thanks, Tim.

[Till Kamppeter (till-kamppeter)]

Uploaded the fixed Ubuntu package for Natty, -0ubuntu16.

[Launchpad Janitor (janitor)]

This bug was fixed in the package system-config-printer - 1.3.1+20110222-0ubuntu16

---------------
system-config-printer (1.3.1+20110222-0ubuntu16) natty; urgency=low

  * debian/patches/67_scp-dbus-service-py-do-not-fail-on-bad-locale.patch:
    Ignore errors of locale.selocale() function calls (LP: #748964).
 -- Till Kamppeter <email address hidden> Mon, 18 Apr 2011 15:33:00 +0200