What steps will reproduce the bug?

1. Invoke bat on a directory and redirect stderr, e.g. bat /bin 2>/dev/null

What happens?

bat outputs to the terminal: [bat error]: '/bin' is a directory.

What did you expect to happen instead?

The STDERR should be redirected to /dev/null, thus no error output should be visible. Looks like bat writes that error to STDOUT instead. Other errors (like when the file does not exist) get written to STDERR, though.