gnome-tweak-tool fails to install extension from zip with UnicodeDecodeError

[Amy C <mathematical coffee gmail com>]

Hi all,

I've written a small extension that adds minimise, maximise, always on
top, etc to the title button on the top panel (Main.panel._appMenu).
I have someone trying to install it through gnome-tweak-tool (on GNOME
3.2.2.1) via 'Shell Extensions' -> 'install extension (from zip file)'
-> select the .zip of the extension.

When they do this they get the following error (discovered by running
gnome-tweak-tool from the terminal):

INFO    : Extracted zip to
/tmp/tmpd9mfyo/window-options mathematical coffee gmail com, copied to
/home/anon/.local/share/gnome-shell/extensions/window-options mathematical coffee gmail com
WARNING : Error parsing theme zip
Traceback (most recent call last):
 File
"/usr/lib/python2.7/dist-packages/gtweak/tweaks/tweak_shell_extensions.py",
line 115, in _on_file_set
   verb = _("%s extension updated successfully") % extension_uuid
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc5 in position 4
ordinal not in range(128)

I initially thought this was a problem with my extension, but now I
think that this *particular* problem is to do with gnome-tweak-tool or
python or something (although who knows, there are probably still
mistakes in my extension too). I think this because I notice the error
is occuring in the "extension updated successfully" part of the
gnome-tweak-tool code as opposed to an error with the extension
itself.

The locale for this user is 'pl_PL.utf8'. Mine is 'en_AU.utf8' and I
can install the extension fine. I cannot reproduce this error as all
my attempts to change my locale so far have failed (even using the
system settings - when I log out & try to log in it does have some
Polish word for 'Password' (I assume) but then once I'm actually
logged in everything reverts back to english and typing `locale` gives
me en_AU.utf8 again).

How can I help this user install the extension, or at least determine
whether it's my extension with the problem or something else?
The user has also tried copying the folder to
~/.local/gnome-shell/extensions & modifying
/org/gnome/shell/enabled-extensions to add the extension, and then it
shows up in gnome-tweak-tool but with an orange exclamation mark next
to it. This seems to indicate to me that there's something wrong with
my extension, but it is working fine on my GNOME 3.2.2.1 & GNOME 3.4
computers (all of which are en_AU.utf8).

I have asked the user to make a .zip of one of their already-working
extensions and try install it in the same way to see if there's a
similar error.

If anyone wants to give this a go, the extension can be downloaded
from the 'Downloads' page here:
https://bitbucket.org/mathematicalcoffee/window-options-gnome-shell-extension
. Pick the .zip file from the 'Downloads' page as this is the version
that the user is having trouble with.

(I do want to eventually put the extension on e.g.o, but only when my
confidence in it has raised a little. i.e. when this problem is
resolved!)

cheers.