Concept: cargo publish automatically running this tool.

[eddyb]

As long as we provide an opt-out, it should be possible for cargo publish to build the most recent semver-compatible version of a crate (as downloaded from crates.io), alongside the about-to-publish version (which I believe already always gets built), and compare them for incompatibilities.

cc @ehuss (I don't know where to suggest this on the Cargo side)

[ehuss]

There is a cargo issue tracking this request: rust-lang/cargo#374

[elichai]

This is an awesome idea, but it seems that there's still a lot of work to do here. #41