default-features = false with hyper-rustls fails

[HollayHorvath]

I had the following line in my Cargo.toml which failed to compile:

yup-oauth2 = { version = "11.0", default-features = false, features = ["hyper-rustls"] }

The error was the following:

error[E0425]: cannot find function `default_crypto_provider` in this scope
    --> /home/.../.cargo/registry/src/index.crates.io-6f17d22bba15001f/yup-oauth2-11.0.0/src/authenticator.rs:1010
:45
     |
1010 |             .with_provider_and_native_roots(default_crypto_provider())?
     |                                             ^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope

error[E0425]: cannot find function `default_crypto_provider` in this scope
    --> /home/.../.cargo/registry/src/index.crates.io-6f17d22bba15001f/yup-oauth2-11.0.0/src/authenticator.rs:1030
:45
     |
1030 |             .with_provider_and_native_roots(default_crypto_provider())
     |                                             ^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope

Simply removing the default-features = false solves the problem, it seems to be a conditional compilation issue.

[dermesser]

Looking at the features, you have to decide between crypto libraries - either use ring or aws-lc-rs. Although I agree that an explicit build error would make users' lives easier at this point.