Bug Report

Version

v0.1.41

Platform

Linux <redacted> 6.6.87.2-microsoft-standard-WSL2 #1 SMP PREEMPT_DYNAMIC Thu Jun 5 18:30:46 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Description

There seems to be a sanitation bug in tracing macros, which produces a compile error if you use debug as one of argument names for string interpolation:

fn main() {
    let debug = false;
    tracing::trace!("debug: {debug:?}");
    tracing::debug!("debug: {debug:?}");
    tracing::warn!("debug:  {debug:?}");
    tracing::info!("debug:  {debug:?}");
    tracing::error!("debug: {debug:?}");
}

This should compile without errors, but we get:

error[E0277]: `fn(_) -> DebugValue<_> {debug::<_>}` doesn't implement `Debug`
 --> tracing_bug/src/main.rs:3:30
  |
3 |     tracing::trace!("debug: {debug:?}");
  |                             -^^^^^---
  |                             ||
  |                             |`fn(_) -> DebugValue<_> {debug::<_>}` cannot be formatted using `{:?}` because it doesn't implement `Debug`
  |                             required by this formatting parameter
  |

(Error help and other similar error messages omitted for brevity).

Notes:

• The issue does not happen if the argument ident is trace, warn, info, or error.

  let trace = false;
  tracing::trace!("debug: {trace:?}");  // compiles
  
  let warn = false;
  tracing::trace!("debug: {warn:?}");  // compiles
  
  let info = false;
  tracing::trace!("debug: {info:?}");  // compiles
  
  let error = false;
  tracing::trace!("debug: {error:?}");  // compiles

• Other macros may be affected, but I have not exhaustively tested it.