error: `trace_macros` is not stable enough for use and is subject to change (see issue #29598) --> $DIR/feature-gate-trace_macros.rs:12:5 | 12 | trace_macros!(true); //~ ERROR: `trace_macros` is not stable | ^^^^^^^^^^^^^^^^^^^^ | = help: add #![feature(trace_macros)] to the crate attributes to enable error: aborting due to previous error