A question pop on stackoverflow today asking about how one could build the doc when build.rs fail because there is not the lib needed to link. The lib should not be needed for a doc build so the question ask about how we could skip the build script somehow.

The solution exist but it's very poorly documented, in the about page ! And https://doc.rust-lang.org/cargo/commands/cargo-metadata.html or https://doc.rust-lang.org/cargo/reference/manifest.html#package-metadata doesn't do better. Would be nice if someone who write better English than me write some doc for it.

Note: I'm surprise this go behind metadata, in my opinion metadata should not affect build, well, this too could be clarify.

rust-lang/rust-playground#192