An HTTP error occurred when trying to retrieve this URL.

 问题背景：conda install xxx 提示 An HTTP error occurred when trying to retrieve this URL.

Fetching package metadata ...
CondaHTTPError: HTTP None None for url <https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main/win-64/repodata.json>
Elapsed: None

An HTTP error occurred when trying to retrieve this URL.
HTTP errors are often intermittent, and a simple retry will get you on your way.
ConnectionError(ReadTimeoutError("HTTPSConnectionPool(host='mirrors.tuna.tsinghua.edu.cn', port=443): Read timed out.",),)

解决办法：找到.condarc文件，将https改为http，删除ssl_verify: true

修改后如下所示

channels:
  - http://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main/
  - http://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/msys2/
  - http://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge
  - http://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/pytorch/
  - http://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/
show_channel_urls: true