Problem with tmux When Upgrading to Yosemite

November 17, 2014

When I updated to Yosemite and started tmux, I get this warning every time I open a new tmux window:

warning: reattach-to-user-namespace: unsupported new OS, trying as if it were 10.6-10.9
warning: _vprocmgr_move_subset_to_user failed
warning: reattach-to-user-namespace: unable to reattach

But running this fixed the problem:

brew update
brew upgrade reattach-to-user-namespace