TIL git doesn't implement its own gitignore spec correctly but ripgrep does so grepping something like the AOSP tree will cause ripgrep to spew dozens of errors.
More seriously, using an env var side steps *a lot* of issues have with command line tools using config files. Such things are far beyond my capacity to explain over twitter. Instead, you can follow along from this comment: https://github.com/BurntSushi/ripgrep/issues/196#issuecomment-362312543 …