$DIR/backtrace-api-v1.rs:13:144 (func_d)
$DIR/backtrace-api-v1.rs:12:50 (func_c)
$DIR/backtrace-api-v1.rs:6:53 (func_b::<u8>)
$DIR/backtrace-api-v1.rs:5:50 (func_a)
$DIR/backtrace-api-v1.rs:17:18 (main)