arm fails to start upon invalid attempt to concatenate int and string

The stack trace is:

Traceback (most recent call last):
  File "./run_arm", line 49, in <module>
    main()
  File "./run_arm", line 18, in main
    arm.starter.main()
  File "/home/pmezard/dev/arm/arm/starter.py", line 94, in main
    curses.wrapper(arm.controller.start_arm)
  File "/usr/lib/python2.6/curses/wrapper.py", line 43, in wrapper
    return func(stdscr, *args, **kwds)
  File "/home/pmezard/dev/arm/arm/controller.py", line 640, in start_arm
    control.redraw(False)
  File "/home/pmezard/dev/arm/arm/controller.py", line 436, in redraw
    panel_impl.redraw(force)
  File "/home/pmezard/dev/arm/arm/util/panel.py", line 428, in redraw
    self.draw(self.max_x, self.max_y)
  File "/home/pmezard/dev/arm/arm/header_panel.py", line 254, in draw
    for label in (self.vals.nickname, " - " + my_address, ":" + self.vals.or_port, dir_port_label):
TypeError: cannot concatenate 'str' and 'int' objects

A possible fix:

commit 57c20fed78a263930e6774f7de47747a1861728a
Author: Patrick Mezard <patrick@mezard.eu>
Date:   Sat Jun 7 23:20:06 2014 +0200

    Fix invalid or_port type formatting when making labels

diff --git a/arm/header_panel.py b/arm/header_panel.py
index 0c7e669..94cf893 100644
--- a/arm/header_panel.py
+++ b/arm/header_panel.py
@@ -251,7 +251,7 @@ class HeaderPanel(panel.Panel, threading.Thread):
 
       dir_port_label = ", Dir Port: %s" % self.vals.dir_port if self.vals.dir_port != "0" else ""
 
-      for label in (self.vals.nickname, " - " + my_address, ":" + self.vals.or_port, dir_port_label):
+      for label in (self.vals.nickname, " - " + my_address, ":%d" % self.vals.or_port, dir_port_label):
         if x + len(label) <= left_width:
           self.addstr(1, x, label)
           x += len(label)

I suppose it comes from:

return [(addr, int(port)) for (addr, port) in proxy_addrs]

done when generating listeners lists in stem. But I understand nothing about the code.

Trac:
Username: pmezard