Static rustc_lint::builtin::UNREACHABLE_PUB[]

pub static UNREACHABLE_PUB: &Lint = &::lint::Lint{name: "UNREACHABLE_PUB",
              default_level: ::lint::Allow,
              desc: "`pub` items not reachable from crate root",
              edition_lint_opts: None,
              report_in_external_macro: false,}
🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?