If you want to have extended and verbose from a command like prove you could pass the verbose -v flag.
$ prove -vIf you however run this command under carton exec
$ carton exec prove -vYou get the version string from carton.
carton v1.0.22
So you have to utilize the -- to terminate command-line argument passing for carton like so:
$ carton exec -- prove -vAnd your test output will be as verbose as you are used to.