val debug: Boolean?
This setting can be used to help debug what's going on with HTTP requests made
by Cargo. When set to true then Cargo's normal debug logging will be filled
in with HTTP information, which you can extract with
CARGO_LOG=cargo::ops::registry=debug (and trace may print more).
Be wary when posting these logs elsewhere though, it may be the case that a header has an authentication token in it you don't want leaked! Be sure to briefly review logs before posting them.