Bug in pyxdg throws error when a client connects

[Markus Ebner]

xpra shadow :0 --bind-tcp=0.0.0.0:10000 -d server

throws an error as soon as a client tries to connect when the pyxdg library is installed.

This because of: ​https://gitlab.freedesktop.org/xdg/pyxdg/-/issues/20

It does not seem that this will be fixed anytime soon, so you may want to catch this (if possible), or temporarily work around this by not attempting to use the library if python is too new.
Verified by uninstalling the python3-pyxdg package. This solved the problem for us.

Stacktrace:

Error during threaded setup of <class 'xpra.server.mixins.child_command_server.ChildCommandServer'>
Traceback (most recent call last):
File "/usr/lib64/python3.8/site-packages/xpra/server/server_base.py", line 172, in threaded_init
c.threaded_setup(self)
File "/usr/lib64/python3.8/site-packages/xpra/server/mixins/child_command_server.py", line 107, in threaded_setup
load_xdg_menu_data()
File "/usr/lib64/python3.8/site-packages/xpra/platform/xposix/xdg_helper.py", line 233, in load_xdg_menu_data
xdg_menu_data = do_load_xdg_menu_data()
File "/usr/lib64/python3.8/site-packages/xpra/platform/xposix/xdg_helper.py", line 264, in do_load_xdg_menu_data
menu = parse()
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 1128, in parse
return XMLMenuBuilder(debug).parse(filename)
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 632, in parse
menu = self.parse_menu(tree.getroot(), filename)
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 650, in parse_menu
self.parse_node(node, filename, menu)
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 659, in parse_node
menu = self.parse_menu(child, filename)
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 650, in parse_menu
self.parse_node(node, filename, menu)
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 682, in parse_node
parent.Rules.append(self.parse_rule(child))
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 759, in parse_rule
return Rule(type, tree)
File "/usr/lib/python3.8/site-packages/xdg/Menu.py", line 421, in __init__
self.code = compile(self.expression, '<compiled-menu-rule>', 'eval')
ValueError: Name node can't be used with 'True' constant

[Markus Ebner]

System Information (Bug-Report tool)

[Antoine Martin]

This was already fixed in r27118, but seeing how often pyxdg throws new types of errors, I've changed the exception handler to catch all exceptions: r27168.
This is normally frowned upon, but better than suffering yet another pyxdg bug in the future.

[Antoine Martin]

There is a viable workaround, launch your server with:

XPRA_EXPORT_XDG_MENU_DATA=0 xpra start ...

Or:

xpra start --env=XPRA_EXPORT_XDG_MENU_DATA=0 ...

[Antoine Martin]

For those unable to upgrade xpra or pyxdg, you can also apply this workaround: ​Bugfix AttributeError: type is not stored in attribute but calculated by method

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/2863