https://bugs.winehq.org/show_bug.cgi?id=51754
--- Comment #7 from Esme Povirk madewokherd@gmail.com --- Looks like the other issues I'm running into are caused by not compiling theme XAML to BAML. clr-namespace: without an assembly and the x:Shared attribute only work in compiled BAML.
We still can't compile BAML because we have no open-source compiler for it. The clr-namespace: issue can be worked around, but we'll need to replace the x:Shared functionality somehow.