无法在模块上控制env_logger VIS RUST_LOG

Question

我遇到了一个问题，即将log/env_logger纳入我的代码。

我已经记录了未释放的记录，如果我在全球级别启用内容（rust_log = debug）或在应用程序级别（rust_log = testlogapp），它似乎可以正常工作）似乎不起作用。

cargo.toml ：

    [package]
    name = "test_log_app"
    version = "0.1.0"
    edition = "2021"
        
    [dependencies]
    env_logger = "0.9.0"
    log = "0.4.16"

src/main.rs

#[macro_use] extern crate log;

fn main() {
    env_logger::init();

    debug!("this is a debug {}", "message");
    error!("this is printed by default");

    let x = 3 * 4; 
    info!("the answer was: {}", x);
}

我得到的结果是：

rust_log = debug - 工作

$ RUST_LOG=debug cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/test_log_app`
[2022-06-22T16:36:40Z DEBUG test_log_app] this is a debug message
[2022-06-22T16:36:40Z ERROR test_log_app] this is printed by default
[2022-06-22T16:36:40Z INFO  test_log_app] the answer was: 12

rust_log = info -

$ RUST_LOG=info cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/test_log_app`
[2022-06-22T16:36:47Z ERROR test_log_app] this is printed by default
[2022-06-22T16:36:47Z INFO  test_log_app] the answer was: 12

按应用程序名称进行作品 rust_log = test_log_app -

$ RUST_LOG=test_log_app cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.00s
     Running `target/debug/test_log_app`
[2022-06-22T16:36:55Z DEBUG test_log_app] this is a debug message
[2022-06-22T16:36:55Z ERROR test_log_app] this is printed by default
[2022-06-22T16:36:55Z INFO  test_log_app] the answer was: 12

模块的作品 rust_log = main - 失败，而没有记录

$ RUST_LOG=main cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
     Running `target/debug/test_log_app`

输出我期望rust_log = main的文档也应启用记录... 我是想念什么还是做错了什么？ 非常感谢

Answer 1

文件main.rs的模块的名称是不是 main。这是板条箱的名称。

证明：

use std::path::PathBuf;

use itertools::Itertools;
use regex::Regex;

fn main() {
    let cargo_toml_path = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("Cargo.toml");
    let cargo_toml = std::fs::read_to_string(cargo_toml_path).unwrap();
    let package_name_regex = Regex::new(r#"name = "(.*)""#).unwrap();
    let crate_name = package_name_regex
        .captures_iter(&cargo_toml)
        .exactly_one()
        .expect("no package name or more than one `name` key in Cargo.toml")
        .get(1)
        .unwrap()
        .as_str();

    println!("file       = {}", file!());
    println!("crate name = {}", crate_name);
    println!("module     = {}", module_path!());
}

：：

file       = src/main.rs
crate name = playground
module     = playground