confusing experience with cargo args

[oconnor663]

I wanted to bisect with a feature enabled in my project. I used this command:

cargo bisect-rustc -- --features=c_avx512

Of course, that's a mistake. I didn't realize that I should have -- build --features=c_avx512 instead of -- --features=c_avx512. However, the mistake was very non-obvious. cargo bisect-rustc just kept downloading older and older nightly versions. Only after I eventually added -vv did I get to see the very helpful error:

Found argument '--features' which wasn't expected, or isn't valid in this context

USAGE:
    cargo [OPTIONS] [SUBCOMMAND]

This is probably going to be a common experience for other folks new to the tool. Maybe it would be better to print all errors by default? Or somehow provide a discoverable fix for issues like the above?