* Fix test usage of `which python`. Also use `command -v` instead of `which` where needed. * Fix testing_formatter.sh file checking. The index is longer expected to exist when generating it. The generation script is run with `set -eux`.
* Fix test usage of `which python`. Also use `command -v` instead of `which` where needed. * Fix testing_formatter.sh file checking. The index is longer expected to exist when generating it. The generation script is run with `set -eux`.