Publishing std to crates.io is much complicated by std’s symbiotic relationship to rustc - it relies on a lot of unstable and version-specific compiler features to operate.
I want to make cross-compiling with Rust easy, but think the solution needs to be more comprehensive than just publishing std somewhere cargo can find it.
My personal ambition is to create a service that builds Rust cross-compile toolchains in every configuration, provides easy installation, and even VM’s on which to run them. I think this can be done as an extension of the Rust compiler’s existing distribution mechanism.