need to use reattach-to-user-namespace

otherwise shell commands hang inside tmux/byobu/etc

work around julienXX/terminal-notifier#115

extensions/10-preexec

@@ -1,5 +1,11 @@
 if command -v terminal-notifier 2>&1 >/dev/null; then
 
+  # https://github.com/julienXX/terminal-notifier/issues/115
+  reattach_cmd=""
+  if command -v reattach-to-user-namespace 2>&1 >/dev/null; then
+      reattach_cmd="reattach-to-user-namespace"
+  fi
+
   preexec_time="0"
 
   preexec() {
@@ -23,7 +29,7 @@ if command -v terminal-notifier 2>&1 >/dev/null; then
          notify="0"
       fi
       if [ $notify -eq "1" ]; then
-  	terminal-notifier -message "$preexec_cmd" -title "Completed after ${diff} seconds"
+  	"$reattach_cmd" terminal-notifier -message "$preexec_cmd" -title "Completed after ${diff} seconds"
       fi
   }