小白学习Rust中 安装evcxr的时候，提示我

Caused by:
  package `evcxr v0.17.0` cannot be built because it requires rustc 1.74 or newer, while the currently active rustc version is 1.73.0

然后我就想到了要去升级Rust版本

然后我使用rustup update命令 但是

info: syncing channel updates for 'stable-x86_64-apple-darwin'
error: could not download file from 'https://static.rust-lang.org/dist/channel-rust-stable.toml.sha256' to '/Users/mmmmmcclxxvii/.rustup/tmp/isx29uja2bne5ysw_file'
info: checking for self-update

  stable-x86_64-apple-darwin update failed - rustc 1.73.0 (cc66ad468 2023-10-03)

info: cleaning up downloads & tmp directories

这里是什么情况？

谢谢帮我答惑