increase rustup fetch default retries and default timeout

[loynoir]

Problem you are trying to solve

Sometimes, got operation timed out: operation timed out.

Seems like static.rust-lang.org connection sometimes not very good.

related

• Rust installer fails with "operation timed out" #2929

• error: could not download file from ... #1328

• Proxy: Cannot download files #2523

Solution you'd like

There are 3 related isssues.

I think, make sense to increase rustup fetch default retries and default timeout.

And add env variable, to let user overwrite them.

https://rust-lang.github.io/rustup/environment-variables.html

Notes

No response