def _build_one_legacy(self, req, tempd, python_tag=None):
base_args = self._base_setup_args(req)<EOL>spin_message = '<STR_LIT>' % (req.name,)<EOL>with open_spinner(spin_message) as spinner:<EOL><INDENT>logger.debug('<STR_LIT>', tempd)<EOL>wheel_args = base_args + ['<STR_LIT>', '<STR_LIT>', tempd]+ self.build_options<EOL>if python_tag is not None:<EOL><INDENT>wheel_args += ["<STR_LIT>", python_tag]<EOL><DEDENT>try:<EOL><INDENT>output = call_subprocess(wheel_args, cwd=req.setup_py_dir,<EOL>show_stdout=False, spinner=spinner)<EOL><DEDENT>except Exception:<EOL><INDENT>spinner.finish("<STR_LIT:error>")<EOL>logger.error('<STR_LIT>', req.name)<EOL>return None<EOL><DEDENT>names = os.listdir(tempd)<EOL>wheel_path = get_legacy_build_wheel_path(<EOL>names=names,<EOL>temp_dir=tempd,<EOL>req=req,<EOL>command_args=wheel_args,<EOL>command_output=output,<EOL>)<EOL>return wheel_path<EOL><DEDENT>
Build one InstallRequirement using the "legacy" build process.

        Returns path to wheel if successfully built. Otherwise, returns None.