tools (common): fixed tty detection when isatty is not available

src/tools/common/ansi.py

@@ -42,8 +42,13 @@ class ANSI(object):
         return u''.join(args)
 
 
-if not sys.stdout.isatty():
+try:
+    tty = sys.stdout.isatty()
+except AttributeError:
+    tty = False
+if not tty:
     # we don't want ANSI escape codes if we are not outputing to a tty!
     for attr in dir(ANSI):
         if isinstance(getattr(ANSI, attr), basestring):
             setattr(ANSI, attr, u'')
+del tty