Rustup: Proxy support is broken in the recent version (rustup 1.22.0 (2d019878d 2020-07-02))

[rohitjoshi]

Problem
Earlier I was able to install/update rust using rustup at my workplace where access is through the proxy.
Today, I was able to successfully update the rustup ( rustup self update ) but after that no longer able to update the toolchain.

See the detail comment : https://www.reddit.com/r/rust/comments/hmaddj/announcing_rustup_1220/fx7eeg2?utm_source=share&utm_medium=web2x

Steps

After updating the rustup to the latest version, try to install tool chain with proxy enabled.

Possible Solution(s)

Notes

Output of rustup --version: rustup 1.22.0 (2d019878d 2020-07-02)
Output of rustup show: Default host: x86_64-apple-darwin
rustup home: /Users/xxx/.rustup

installed toolchains

stable-x86_64-apple-darwin
beta-x86_64-apple-darwin
nightly-2019-03-24-x86_64-apple-darwin
nightly-2019-04-03-x86_64-apple-darwin
nightly-x86_64-apple-darwin (default)

active toolchain

nightly-x86_64-apple-darwin (default)
rustc 1.46.0-nightly (fd4b177aa 2020-06-08)

[kinnison]

Hi, I'm sorry you encountered this. @inejge noticed this and provided an updated env_proxy and #2399 last night, and we're trying to get a release out ASAP. I'll close this once 1.22.1 is out.

[alaric]

In case anyone is stuck with this, falling back to curl by setting RUSTUP_USE_CURL=1 as a temporary workaround worked in my environment.

[rohitjoshi]

Thanks @alaric for the workaround.

[kinnison]

1.22.1 is out and should be fixed.