unzip: cannot find zipfile directory in one of

下面是执行flutter doctor 后报错内容

End-of-central-directory signature not found. Either this file is not
a zipfile, or it constitutes one disk of a multi-part archive. In the
latter case the central directory and zipfile comment will be found on
the last disk(s) of this archive.
unzip: cannot find zipfile directory in one of /Users/liubo/Documents/flutter/bin/cache/dart-sdk-darwin-x64.zip or
/Users/liubo/Documents/flutter/bin/cache/dart-sdk-darwin-x64.zip.zip, and cannot find /Users/liubo/Documents/flutter/bin/cache/dart-sdk-darwin-x64.zip.ZIP, period.
It appears that the downloaded file is corrupt; please try again.
If this problem persists, please report the problem at:
https://github.com/flutter/flutter/issues/new?template=1_activation.md

解决方法

配置flutter 环境地质

export PUB_HOSTED_URL=https://pub.flutter-io.cnexport FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn