Comment 1 for bug 1873368

The python docs [0] indicate that the file descriptor should be a socket:
"The file descriptor should refer to a socket, but this is not checked — subsequent operations on the object may fail if the file descriptor is invalid."

The docs do need to be corrected. bpo#35415 now explicitly checks fd to ensure they are sockets.

The fix for this issue likely needs to be in sshuttle, not python.

[0] https://docs.python.org/3/library/socket.html#socket.fromfd