For nearly the last two years, I've been doing most of my development in OS X. Most of that development has been done in Clojure and, whenever possible, using lein-test-refresh with terminal-notifier to have my tests automatically run and a notification shown with the status of the test run. Its a great work flow that gives me a quick feedback cycle and doesn't pull my attention in different directions.

Recently I've started using tmate for remote pairing. Unfortunately when I first started using it my quick feedback cycle was broken. lein test-refresh would run my tests but would become hung when sending a notification using terminal-notifier. This was terrible and, if I hadn't been able to fix it, would have stopped me from using tmate. After some searching I stumbled across this GitHub issue which helped solve the problem.

To make tmate work nicely with terminal-notifier you'll need to install reattach-to-user-namespace and change your tmate configuration to use it. If you use brew you can install by running `brew install –with-wrap-pbcopy-and-pbpaste reattach-to-user-namespace. Then open your .tmux.conf` or .tmate.conf file and add the line below.

set-option -g default-command "which reattach-to-user-namespace > /dev/null && reattach-to-user-namespace -l $SHELL || $SHELL"

The above tells tmate to use reattach-to-user-namespace if it is available. Now terminal-notifier no longer hangs when invoked inside tmate. Unsurprisingly, this change also makes tmux place nice with terminal-notifier.