Whilst working on update-manager I have been wondering whether I should use gettext for localizing debug output and error messages sent to stderr.
As for debug output itself I basically do not see the need for providing a localized version for each and every message sent to stderr, but as far as error messages are concerned I am uncertain.
The point is that update-manager (apart from its experimental text interface) is usually not launched from a terminal at all and so most users won't even see these messages ever. Also, I believe that every developer's English skills are good enough so that he or she is able to understand simple messages.
Error messages however might be useful to all users when they experience a problem with the software, but localizing those could make handling bug reports a bit harder, possibly having to translate the error message back to English before being able to see what has gone wrong.
So basically I am asking you: What do you think? Is it worth localizing these messages? What is your experience with localized or non-localized error and debug messages?
I would be glad if I could get some input from you, either as a comment to this article, via email to debian(dot)sp(dot)or(dot)at or through the update-manager-devel mailing list.