cargo run -p compiletest -- --help

$ cargo run -p compiletest -- --help
    Finished dev [unoptimized + debuginfo] target(s) in 0.03s
     Running `target/debug/compiletest --help`
Usage: target/debug/compiletest [OPTIONS] [TESTNAME...]

Options:
        --compile-lib-path PATH
                        path to host shared libraries
        --run-lib-path PATH
                        path to target shared libraries
        --rustc-path PATH
                        path to rustc to use for compiling

<snip>

        --force-rerun   rerun tests even if the inputs are unchanged
    -h, --help          show this message
        --edition EDITION
                        default Rust edition


thread 'main' panicked at 'explicit panic', tools/compiletest/src/main.rs:158:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace