create-key prints no progress

When I use snapcraft create-key, it takes a long time to finish but it prints nothing to the terminal about the things it's running and the progress it's making. That's not nice for the user, you might think it's stuck, and you are left wondering why it's taking so long.

elopio@ubuntu-xenial:~/snapcraft$ date
lun 3 oct 12:43:07 CST 2016
elopio@ubuntu-xenial:~/snapcraft$ ./bin/snapcraft create-key
Passphrase:
Confirm passphrase:
elopio@ubuntu-xenial:~/snapcraft$ date
lun 3 oct 13:01:10 CST 2016

In addition to that, it took too long probably because it was collecting entropy. But it didn't explain that. This was on a vm that I left idle while doing something else. When I returned it was still stuck, so I used rngd to speed it up.