capybara/virtualenv/lib/python2.7/site-packages/pip/req/req_install.py
def ensure_has_source_dir(self, parent_dir):
        """Ensure that a source_dir is set.

        This will create a temporary build dir if the name of the requirement
        isn't known yet.

        :param parent_dir: The ideal pip parent_dir for the source_dir.
            Generally src_dir for editables and build_dir for sdists.
        :return: self.source_dir
        """
        if self.source_dir is None:
            self.source_dir = self.build_location(parent_dir)
        return self.source_dir
def ensure_has_source_dir(self, parent_dir):
        if self.source_dir is None:
            self.source_dir = self.build_location(parent_dir)
        return self.source_dir
def ensure_has_source_dir ( self , parent_dir ) : if self . source_dir is None : self . source_dir = self . build_location ( parent_dir ) return self . source_dir
Ensure that a source_dir is set.

        This will create a temporary build dir if the name of the requirement
        isn't known yet.

        :param parent_dir: The ideal pip parent_dir for the source_dir.
            Generally src_dir for editables and build_dir for sdists.
        :return: self.source_dir
Ensure that a source_dir is set .