Build issues on s390x/ppc64 on Fedora

Hi folks,

I'm the maintainer of task in Fedora. I've finally managed to get version 3 building on our build system, by vendoring the rust-deps as noted in the developer docs. It builds on all architectures apart from s390x and ppc64le. The errors on these seem to be related to aws-lc-sys, which doesn't apparently build on these architectures without heavy patching (which one can't trivially do when using vendored crates).

While looking into this and discussing it with Fedora Rust folks, it was pointed out to me that that the build also pulls in two crypto libraries instead of one (ring and aws-lc-rs)---and apparently this points to inconsistencies in the dependency chain and should not be happening? (my rust is quite rusty, so I'm relaying bits that I've been told here :))