message: Move trace log to a span
diff: @@ -15,7 +15,7 @@ use std::env;
  use std::ffi::CString;
  use std::fs::create_dir_all;
  use std::path::{Path, PathBuf};
  -use tracing::{debug, error, info, trace, warn};
  +use tracing::{debug, error, info, trace_span, warn};
  use tracing_subscriber::{filter::LevelFilter, EnvFilter};
  pub mod branching;
  @@ -264,7 +264,8 @@ fn collect_coverage(
  let mut ret_code = 0;
  let mut traces = generate_tracemap(test_path, analysis, config)?;
  {
  - trace!("Test PID is {}", test);
  + let span = trace_span!("Collect coverage", pid=%test);
  + let _enter = span.enter();
  let (mut state, mut data) = create_state_machine(test, &mut traces, config, logger);
  loop {
  state = state.step(&mut data, config)?;
  