error[E0432]: unresolved import `libc` --> $DIR/issue-37887.rs:13:9 | LL | use libc::*; //~ ERROR unresolved import | ^^^^ maybe a missing `extern crate libc;`? error[E0658]: use of unstable library feature '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? (see issue #27812) --> $DIR/issue-37887.rs:12:5 | LL | extern crate libc; //~ ERROR use of unstable | ^^^^^^^^^^^^^^^^^^ | = help: add #![feature(rustc_private)] to the crate attributes to enable error: aborting due to 2 previous errors Some errors occurred: E0432, E0658. For more information about an error, try `rustc --explain E0432`.