Comment 38 for bug 525552

+1 for the workarounds from @readan2 in #33. Using a mbp5,3 on OSX 10.9.1, with byobu and tmux from homebrew. I don't understand the reasons for wanting to avoid a login shell, but I can report that adding "--login" in the three places shown below gets my $PS1 back the way it's supposed to be.
  1) /usr/local/bin/byobu-shell: exec "$SHELL" --login || exec /bin/sh --login
  2) /usr/local/share/byobu/profiles/tmux: set -g default-command $SHELL --login

A separate, unrelated point, is that homebrew does not ship the python snack module in its libnewt, so byobu-config does not work. :(