JHBuild bootstrap failed

macbook-pro-di-zhu-francesco-yangfan:~ francesco$ jhbuild bootstrap
Traceback (most recent call last):
  File "/Users/francesco/Source/jhbuild/jhbuild/config.py", line 212, in load
    execfile(self.filename, config)
  File "/Users/francesco/.jhbuildrc", line 90, in <module>
    _xcodeversion = xcode_ver()
  File "/Users/francesco/.jhbuildrc", line 89, in xcode_ver
    return float(exp.match(_ver).group(1))
AttributeError: 'NoneType' object has no attribute 'group'
jhbuild: could not load config file