Static rustc_lint::builtin::NO_MANGLE_CONST_ITEMS[]

static NO_MANGLE_CONST_ITEMS: &Lint = &::lint::Lint{name: "NO_MANGLE_CONST_ITEMS",
              default_level: ::lint::Deny,
              desc: "const items will not have their symbols exported",
              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?