This is a tracking issue for the RFC "Minimum Supported Rust Version" (rust-lang/rfcs#2495).

Note: There is a separate tracking issue on the Cargo side at: rust-lang/cargo#8072

Documentation: https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field

Steps:

• Implement the RFC (cc @rust-lang/cargo -- can anyone write up mentoring
  instructions?)
• Adjust documentation (see instructions on rustc-guide)
• Stabilization PR (see instructions on rustc-guide)

Unresolved questions:

• Name bike-shedding: rust vs rustc vs min-rust-version
• Additional checks?
• Better description of versions resolution algorithm.
• How nightly versions will work with "cfg based MSRV"?