$DIR/backtrace-api-v0.rs:11:59 (func_d)
$DIR/backtrace-api-v0.rs:10:50 (func_c)
$DIR/backtrace-api-v0.rs:4:53 (func_b)
$DIR/backtrace-api-v0.rs:3:50 (func_a)
$DIR/backtrace-api-v0.rs:15:18 (main)