After getting my cable working so Chirp can download (clone) from my VX-6, now it hangs on the upload! This doesn't appear to be cable related – things start to go south in the debug log (below) with some file permission errors. But I installed this from an account with full admin privileges and run it from that same account. And is the eventual failure because of this?
No, those are just fallout from GTK trying to save stuff, unrelated to anything CHIRP is doing. As you can see, they're not permissions-related, but rather complaining that some directory doesn't exist (probably ~/.local). You can try to create that and see if they go away, but I doubt they're related to your issue.
The clone/Tx progress bar indicates the transmission at least gets started before the hang…
And what does the radio do? I assume it starts and then times out waiting for the computer? It's far enough that it's sent at least the header block to the radio and received the ACK.
Based on your stack trace, it's just in a dead-simple loop writing data out to the serial port. It's not even looking for a response from the radio. The number of things that could cause this all lie fairly low, such as the driver for your cable, your cable, etc. If you wait long enough for that to complete, then you should get another error about not getting a response from the radio. If you never get that, then CHIRP is blocked writing to the serial port against its will, which screams of a driver issue.
It seems like MacOS users always have lots of trouble finding stable/suitable drivers for their USB dongles. The ones that persevere eventually find one that works, and the ones that don't, well...don't.
Unfortunately, I don't even own a physical Mac so there's not a whole lot I can do to help. There are a lot of folks successfully using the MacOS build with a variety of radios.
Maybe someone else on this list that actually uses MacOS could chime in with some suggestions for you...