How to avoid [3ma[0m[2m= in file log properly?

[failable]

use std::io;

use tracing::{debug, error, info, instrument, level_filters::LevelFilter, warn};
use tracing_subscriber::{Layer, layer::SubscriberExt, util::SubscriberInitExt};

#[instrument]
fn test(a: i32, b: &str) {
    info!("Hello world!");
    error!("An error occurs!");
    debug!("Debug message");
    warn!("A warning message");
}

fn main() {
    let file_appender = tracing_appender::rolling::daily("log/", "output.log");
    let (non_blocking, _guard) = tracing_appender::non_blocking(file_appender);

    let stdout_layer = tracing_subscriber::fmt::layer().with_writer(io::stdout);
    let mut file_layer = tracing_subscriber::fmt::layer()
        .with_ansi(false) // NOT working?
        .with_writer(non_blocking);
    file_layer.set_ansi(false); // NOT working?

    let layers = vec![
        stdout_layer.with_filter(LevelFilter::INFO).boxed(),
        file_layer.with_filter(LevelFilter::INFO).boxed(),
    ];
    tracing_subscriber::registry().with(layers).init();

    test(42, "test");
}

The script still generate contents like

2025-03-12T03:44:26.612385Z  INFO test{�[3ma�[0m�[2m=�[0m42 �[3mb�[0m�[2m=�[0m"test"}: project: Hello world!
2025-03-12T03:44:26.612435Z ERROR test{�[3ma�[0m�[2m=�[0m42 �[3mb�[0m�[2m=�[0m"test"}: project: An error occurs!
2025-03-12T03:44:26.612463Z  WARN test{�[3ma�[0m�[2m=�[0m42 �[3mb�[0m�[2m=�[0m"test"}: project: A warning message

Running NO_COLOR seems OK but it also disable color and other format for terminal output. I'd like to disable it in file only. How should I do? Thanks.

[kaffarell]

This is because the formatted fields are not stored properly and only one action (ansi=true or ansi=false) is recorded. This should be fixed with #3221. In the meantime you can put the stdout_layer above the file_layer in the layers vec, so:

let layers = vec![
      file_layer.with_filter(LevelFilter::INFO).boxed(),
      stdout_layer.with_filter(LevelFilter::INFO).boxed(),
  ];

This will trigger the no-ansi formatted fields to be inserted first.