Xpra: Ticket #1571: python3 server support

Split from #1568.

From easiest to hardest:



Sun, 23 Sep 2018 05:19:15 GMT - Antoine Martin: status changed; resolution set

Dupe of #853


Sat, 23 Jan 2021 05:28:01 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1571