message: [log] Fix env logger level get.
diff: @@ -134,7 +134,8 @@ fn build_config(arg: LoggerConfigArg) -> Result<Config> {
  }
  fn env_log_level(default_level: &str) -> LevelFilter {
  - let level = option_env!("RUST_LOG").unwrap_or(default_level);
  + let level = std::env::var("RUST_LOG").unwrap_or(default_level.to_string());
  + println!("Log level: {:?}", level);
  level
  .parse()
  .expect(format!("Unexpect log level: {}", level).as_str())
  @@ -170,7 +171,7 @@ mod tests {
  #[test]
  fn test_log() {
  super::init_for_test();
  - debug!("debug message.");
  + debug!("debug message2.");
  info!("info message.");
  warn!("warn message.");
  error!("error message.");
  