Cargo main function logging

[leonjia0112]

When I put the example in main.rs. Ran with RUST_LOG=main=trace cargo run. Nothing was print out. It is an issue with pretty_env_logger or cargo itself? Because running RUST_LOG=trace cargo run will print out everything, which is not what we want.

[seanmonstar]

You need to use the name of the crate, like RUST_LOG=your_app=trace.