Rust版本升级
升级Rust版本
官方方式
通过 rustup 安装了 Rust 之后，更新到最新版本只要运行如下更新脚本：
$ rustup update
尝试在mac下从 1.40 升级到 1.42 成功，输出如下：
$ rustup update
info: syncing channel updates for 'stable-x86_64-apple-darwin'
463.3 KiB / 463.3 KiB (100 %) 414.2 KiB/s in 1s ETA: 0s
info: latest update on 2020-03-12, rust version 1.42.0 (b8cedc004 2020-03-09)
info: downloading component 'rust-src'
2.2 MiB / 2.2 MiB (100 %) 313.6 KiB/s in 8s ETA: 0s
info: downloading component 'cargo'
3.7 MiB / 3.7 MiB (100 %) 321.3 KiB/s in 14s ETA: 0s
info: downloading component 'clippy'
1.3 MiB / 1.3 MiB (100 %) 327.7 KiB/s in 5s ETA: 0s
info: downloading component 'rust-docs'
12.1 MiB / 12.1 MiB (100 %) 323.2 KiB/s in 43s ETA: 0s
info: downloading component 'rust-std'
16.1 MiB / 16.1 MiB (100 %) 345.6 KiB/s in 1m 3s ETA: 0s
info: downloading component 'rustc'
54.5 MiB / 54.5 MiB (100 %) 342.4 KiB/s in 4m 20s ETA: 0s
info: downloading component 'rustfmt'
1.9 MiB / 1.9 MiB (100 %) 288.0 KiB/s in 7s ETA: 0s
info: removing previous version of component 'rust-src'
info: removing previous version of component 'cargo'
info: removing previous version of component 'clippy'
info: removing previous version of component 'rust-docs'
info: removing previous version of component 'rust-std'
info: removing previous version of component 'rustc'
info: removing previous version of component 'rustfmt'
info: installing component 'rust-src'
info: installing component 'cargo'
info: installing component 'clippy'
info: installing component 'rust-docs'
12.1 MiB / 12.1 MiB (100 %) 8.6 MiB/s in 1s ETA: 0s
info: installing component 'rust-std'
info: installing component 'rustc'
54.5 MiB / 54.5 MiB (100 %) 18.3 MiB/s in 3s ETA: 0s
info: installing component 'rustfmt'
info: checking for self-updates
stable-x86_64-apple-darwin updated - rustc 1.42.0 (b8cedc004 2020-03-09) (from rustc 1.40.0 (73528e339 2019-12-16))
info: cleaning up downloads & tmp directories
尝试在linux 下从 1.54.0 升级到 1.55.0 成功，输出如下：
➜ ~ rustup update
info: syncing channel updates for 'stable-x86_64-unknown-linux-gnu'
679.5 KiB / 679.5 KiB (100 %) 463.5 KiB/s in 1s ETA: 0s
info: latest update on 2021-09-09, rust version 1.55.0 (c8dfcfe04 2021-09-06)
info: downloading component 'rust-src'
info: downloading component 'cargo'
6.1 MiB / 6.1 MiB (100 %) 4.4 MiB/s in 1s ETA: 0s
info: downloading component 'clippy'
info: downloading component 'rust-docs'
17.0 MiB / 17.0 MiB (100 %) 4.5 MiB/s in 3s ETA: 0s
info: downloading component 'rust-std'
22.3 MiB / 22.3 MiB (100 %) 4.6 MiB/s in 5s ETA: 0s
info: downloading component 'rustc'
51.0 MiB / 51.0 MiB (100 %) 4.2 MiB/s in 11s ETA: 0s
info: downloading component 'rustfmt'
info: removing previous version of component 'rust-src'
info: removing previous version of component 'cargo'
info: removing previous version of component 'clippy'
info: removing previous version of component 'rust-docs'
info: removing previous version of component 'rust-std'
info: removing previous version of component 'rustc'
info: removing previous version of component 'rustfmt'
info: installing component 'rust-src'
info: installing component 'cargo'
info: installing component 'clippy'
info: installing component 'rust-docs'
17.0 MiB / 17.0 MiB (100 %) 11.3 MiB/s in 1s ETA: 0s
info: installing component 'rust-std'
22.3 MiB / 22.3 MiB (100 %) 16.7 MiB/s in 1s ETA: 0s
info: installing component 'rustc'
51.0 MiB / 51.0 MiB (100 %) 18.9 MiB/s in 2s ETA: 0s
info: installing component 'rustfmt'
info: checking for self-updates
stable-x86_64-unknown-linux-gnu updated - rustc 1.55.0 (c8dfcfe04 2021-09-06) (from rustc 1.54.0 (a178d0322 2021-07-26))
info: cleaning up downloads & tmp directories
如果要卸载 Rust 和 rustup，运行如下卸载脚本:
$ rustup self uninstall
归档内容：曾经遇到的升级问题
尝试过升级已经安装的rust/cargo，试图从1.22.1升级到1.23，发现重新运行rustup脚本，虽然报告说安装成功，但是实际不会安装新的版本。
暂时没有找到升级的方法，只好用最笨的办法，先删除再全新安装：
cd
rm -rf .cargo/ .rustup/
这个方式理所当然的很不好，原有的所有内容都要重头来一次。
后面似乎没有再遇到类似问题。