This killed all shell interaction within my tmux setup, somehow, and I had to downgrade in osx/brew [1] back to v3.4.1 [2]. I'm still wondering what part of my (probably outdated) tmux config caused it, but the most suspicious part is the run-shell/if-shell stuff.

Anyway, have things to do before I can try again and dig in. Thought I'd post in case someone else ran into this.

[Edit] Tip: swap to a different shell before uninstalling your current shell. Sigh...lol

[1] https://github.com/fish-shell/fish-shell/issues/5497 [2] https://raw.githubusercontent.com/Homebrew/homebrew-core/ad5...