I don't think I ever actually wrote something about this. I need to write a post about this. The only reason I didn't is because I didn't want to mess with the Linuxulator on FreeBSD and, later, because I didn't want to attempt to build Proton bridge from source. On linux, it seems to work file.

I might try to build it again on {free,open}bsd to try to remember what the issue was.