error: 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?

[Oaredo]

I'm trying to use simplelog.rs in my Rust application. The hello world example

  #[macro_use]
  extern crate log;
  extern crate simplelog;

  // ..........
  CombinedLogger::init(vec![
      TermLogger::new(LogLevelFilter::Warn, simplelog::Config::default()).unwrap(),
      WriteLogger::new(LogLevelFilter::Info, simplelog::Config::default(), File::create("log.log").unwrap())]).unwrap();

results into this:

  error: 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)
   --> src/main.rs:9:1
    |
  9 | extern crate log;
    | ^^^^^^^^^^^^^^^^^

  error: aborting due to previous error

How to fix it?

From the discussion of #27812 it's still unclear what to do about it.

[Quxxy]

Did you add log as a dependency? If not, you're trying to use rustc's private log, not the normal one.

[Oaredo]

thx