下载YOLOv5
git clone https://github.com/ultralytics/yolov5
问题一：
fatal: unable to access 'https://github.com/ultralytics/yolov5/': gnutls_handshake() failed: The TLS connection was non-properly terminated.
解决方法： 将https改成git
git clone git://github.com/ultralytics/yolov5
参考：https://www.cnblogs.com/zukang/p/14832868.html （如果侵权，速删）
问题二：
fatal: remote error:
The unauthenticated git protocol on port 9418 is no longer supported.
Please see https://github.blog/2021-09-01-improving-git-protocol-security-github/ for more information.
解决方法：
git config --global url."https://".insteadOf git://
参考：https://blog.csdn.net/dp30737/article/details/123697382（如果侵权，速删）
