EnvFilter seems not working correctly

[uuhan]

Bug Report

use tracing::Level;
use tracing_subscriber::filter::{EnvFilter, LevelFilter};
fn main() {
    let filter = EnvFilter::from_default_env()
        .add_directive("[span0]=info".parse().unwrap())          // <- span0's log lever: INFO
        .add_directive("warn".parse().unwrap());                 // <- default log level: WARN

    tracing_subscriber::fmt().with_env_filter(filter).init();

    let span = tracing::span!(Level::INFO, "span0");
    let _span = span.enter();

    tracing::info!("log info");   // <- this SHOULD log
}

Output: INFO span0: test_tracing: log info // <- expected

use tracing::Level;
use tracing_subscriber::filter::{EnvFilter, LevelFilter};
fn main() {
    let filter = EnvFilter::from_default_env()
        .add_directive("[span0]=warn".parse().unwrap())             // <- span0's log level: WARN
        .add_directive("info".parse().unwrap());                    // <- default log level: INFO
 
    tracing_subscriber::fmt().with_env_filter(filter).init();

    let span = tracing::span!(Level::INFO, "span0");
    let _span = span.enter();        

    tracing::info!("log info");   // <- this SHOULD NOT log
}

Output: INFO span0: test_tracing: log info // <- NOT expected

Version

├── tracing v0.1.28
│   ├── tracing-attributes v0.1.16 (proc-macro)
│   └── tracing-core v0.1.20
├── tracing-appender v0.1.2
│   └── tracing-subscriber v0.2.24
│       ├── tracing v0.1.28 (*)
│       ├── tracing-core v0.1.20 (*)
│       ├── tracing-log v0.1.2
│       │   └── tracing-core v0.1.20 (*)
│       └── tracing-serde v0.1.2
│           └── tracing-core v0.1.20 (*)
└── tracing-subscriber v0.2.24 (*)

Platform

macOS

Description

see bug report

[uuhan]

Maybe the question is:

Is there any way to opt-out some module/span's INFO log when I keep all the other INFO logs?

[davidbarsky]

This is an unfortunate behavior of EnvFilter, in that it treats a match in a single directive's match as a match for everything else.

Is there any way to opt-out some module/span's INFO log when I keep all the other INFO logs?

I suggest giving https://docs.rs/tracing-subscriber/0.2.24/tracing_subscriber/filter/struct.FilterFn.html a try.

[uuhan]

Hope to change the EnvFilter design to work like a real "env filter" one, just like other log crates(like log4rs) do.

FilterFn is not very proper for my app.