error[E0432]: unresolved import `libc`
  --> $DIR/issue-37887.rs:3:9
   |
LL |     use libc::*;
   |         ^^^^ maybe a missing crate `libc`?
   |
   = help: consider adding `extern crate libc` to use the `libc` crate

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?
  --> $DIR/issue-37887.rs:2:5
   |
LL |     extern crate libc;
   |     ^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #27812 <https://github.com/rust-lang/rust/issues/27812> for more information
   = help: add `#![feature(rustc_private)]` to the crate attributes to enable

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0432, E0658.
For more information about an error, try `rustc --explain E0432`.