* usr/lib/byobu/.dirs:

- fix breakage when $TMUX is undefined

debian/changelog

@@ -4,6 +4,8 @@ byobu (4.31) unreleased; urgency=low
     - fix bold color printing
   * usr/bin/byobu-janitor, usr/share/byobu/profiles/common:
     - deprecate backticks file, no longer needed
+  * usr/lib/byobu/.dirs:
+    - fix breakage when $TMUX is undefined
 
  -- Dustin Kirkland <kirkland@ubuntu.com>  Sun, 21 Aug 2011 21:12:43 -0700
 

usr/lib/byobu/.dirs

@@ -44,7 +44,7 @@ if [ -d "$XDG_CACHE_HOME" ]; then
 elif [ -d "$SOCKETDIR/S-$USER" ]; then
 	# But for FAR better performance, use a tmpfs if available
 	export BYOBU_RUN_DIR="$SOCKETDIR/S-$USER/$PKG"
-elif [ -d "$(dirname $TMUX)" ]; then
+elif [ -n "$TMUX" ] && [ -d "$(dirname $TMUX)" ]; then
 	# Or perhaps try the tmux tmpdir
 	export BYOBU_RUN_DIR="$(dirname $TMUX)/$PKG"
 else