This repository is basically what you would get after running cargo init and cargo fuzz init, in addition to a dependency on rustc_ap_rustc-span, a trivial use of this dependency in src/lib.rs and a reference to that use in fuzz/fuzz_targets/fuzz_target_1.rs.

To get the error message simply run cargo fuzz run fuzz_target_1

The error message (with RUST_BACKTRACE=full) can be found in error_msg.txt