Static rustc_lint::builtin::MISSING_COPY_IMPLEMENTATIONS[]

pub static MISSING_COPY_IMPLEMENTATIONS: &Lint = &::lint::Lint{name: "MISSING_COPY_IMPLEMENTATIONS",
              default_level: ::lint::Allow,
              desc: "detects potentially-forgotten implementations of `Copy`",
              edition_lint_opts: None,}
🔬 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?