When using cross.rs for comilation, sse and sse2 break the build.

[guenhter]

Hi,

when I run this:

# Install cross.rs
cargo install cross --git https://github.com/cross-rs/cross

# Create some project
cargo new foo
cd foo
cargo add ring

# Build it
cross build --release --target i586-unknown-linux-musl

I get this error:

cross build --release --target i586-unknown-linux-musl
   Compiling shlex v1.3.0
   Compiling libc v0.2.158
   Compiling cfg-if v1.0.0
   Compiling spin v0.9.8
   Compiling untrusted v0.9.0
   Compiling cc v1.1.13
   Compiling getrandom v0.2.15
   Compiling ring v0.17.8
error[E0080]: evaluation of constant value failed
  --> /home/foo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/ring-0.17.8/src/cpu/intel.rs:28:9
   |
28 |         assert!(cfg!(target_feature = "sse") && cfg!(target_feature = "sse2"));
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'assertion failed: cfg!(target_feature = "sse") && cfg!(target_feature = "sse2")', /home/foo/.cargo/registry/src/index.crates.io-6f17d22bba15001f/ring-0.17.8/src/cpu/intel.rs:28:9
   |
   = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try `rustc --explain E0080`.
error: could not compile `ring` (lib) due to 1 previous error

Did anyone manage to cross build with cross.rs?

[guenhter]

This should be enough as answer #1999