1339176 - Set default rust log level to warn on debug builds

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Bobby Holley (:bholley)]

We don't really have a great equivalent of NS_WARNING for rust code right now. warn!() is disabled by default, and error!() runs in release builds.

We should configure gecko somehow so that --enable-debug builds set the Rust's log level to 'warn'.

Comment 1

[(not currently active) Ted Mielczarek]

It looks like env_logger has support for parsing the log level from a string now:
https://docs.rs/env_logger/0.4.0/env_logger/struct.LogBuilder.html#method.parse

We could do something like:
``
let mut builder = LogBuilder::new();
match env::var("RUST_LOG") {
  Ok(v) => builder.parse(&v).init(),
  _ => builder.parse("warn").init(),
}
```

We'd have to call that during startup, obviously.

Comment 2

[Bobby Holley (:bholley)]

Doing this in https://github.com/servo/servo/pull/15557