Also tried setting tramp-verbose to a high value and I see the traces on *trace-output* but no errors. The freeze only happens if the remote file buffer is visible when switching back to emacs 🤷 I guess I'll try upgrading, no idea what else to do

I'd try using Emacs 26, 27, 28 from https://emacsformacosx.com/ (these are vanilla builds) and the most minimal .emacs.d that you'd be comfortable with

emacs -q doesn't have any effect, I might downgrade to emacs 28

or upgrade to emacs 30 😄

I'm just unhappy I couldn't even get a trace of the error, it's not like it's the first time emacs has died on me, but at least it had the courtesy to tell me why

My m2 macbook's emacs is v30.0.50, and tramp works fine; I did have to do something to my fish config on boxes I tramp'ed to, though; there might be a similar issue with zsh. https://github.com/oh-my-fish/theme-bobthefish/issues/148

Thanks for the report! I'll try upgrading during the weekend. The prompt ssh is an interesting point I hadn't considered, but sadly(?) the remote server has stock bash

my immediate reaction is wondering if it waits for a prompt yes. Happened to me, too.

I hadn't seen one, but since the whole ui freezes maybe it is there somewhere. The puzzling thing is also when it happens, 100% after switching from Emacs to another app and then back.

Maybe there's some "on focus in" hook? Worth inspecting