Merge branch 'wrywerytwreywery-vt_prompt'

xonsh/built_ins.py

@@ -54,6 +54,8 @@ class Env(MutableMapping):
             return self._detyped
         ctx = {}
         for key, val in self._d.items():
+            if callable(val):
+                continue
             if not isinstance(key, string_types):
                 key = str(key)
             if 'PATH' in key:

xonsh/shell.py

@@ -181,7 +181,6 @@ class Shell(Cmd):
             p = env['PROMPT']
             if callable(p):
                 p = p()
-            else:
             p = format_prompt(p)
         else:
             p = "set '$PROMPT = ...' $ "