def get_magic_comment(self, name, expand_macros=False):
        """Return a value of # name=value comment in spec or None."""
        match = re.search(r'^#\s*?%s\s?=\s?(\S+)' % re.escape(name),
                          self.txt, flags=re.M)
        if not match:
            return None

        val = match.group(1)
        if expand_macros and has_macros(val):
            # don't parse using rpm unless required
            val = self.expand_macro(val)
        return val