Tmux Copy Mode
Last week we encountered a breaking change in our Tmux configuration, and briefly lost the ability to scroll with the mouse. It became an opportunity to re-learn Tmux's copy mode, and liberate ourselves from the mouse a little more.
Enter copy mode with
<prefix> [. From here, you can navigate with standard Vim commands.
ctrl-u moves you a half-page up, perfect for wading through test failure backtraces.