--print Options
The behavior of the --print flag can be modified by optionally be specifying a filepath
for each requested information kind, in the format --print KIND=PATH, just like for
--emit. When a path is specified, information will be written there instead of to stdout.
This is unstable feature, so you have to provide -Zunstable-options to enable it.
Examples
rustc main.rs -Z unstable-options --print cfg=cfgs.txt