Cryptsetup calls clevis too late

[Vin Shelton]

This works:
  echo "Hello World..." | clevis encrypt tang '{ "url": "http://192.168.xx.yy"}' > secret.jwe
The advertisement contains the following signing keys:

XXXXXX_FFGnNkN9b72vXkkEMz24vdmcvhT-xCc27boA

Do you wish to trust these keys? [ynYN] y
  clevis decrypt <secret.jwe
Hello World...

But this doesn't work (the luksOpen prompts on the terminal for a password):
  sudo cryptsetup luksFormat /dev/sda3
WARNING: Device /dev/sda3 already contains a 'crypto_LUKS' superblock signature.

WARNING!
========
This will overwrite data on /dev/sda3 irrevocably.

Are you sure? (Type 'yes' in capital letters): YES
Enter passphrase for /dev/sda3:
Verify passphrase:
  sudo clevis luks bind -d /dev/sda3 tang '{"url":"http://192.168.xx.yy"}'
Enter existing LUKS password:
Warning: Value 512 is outside of the allowed entropy range, adjusting it.
The advertisement contains the following signing keys:

XXXXXX_FFGnNkN9b72vXkkEMz24vdmcvhT-xCc27boA

Do you wish to trust these keys? [ynYN] y
  sudo cryptsetup luksOpen /dev/sda3 asdf
Enter passphrase for /dev/sda3: Error reading passphrase from terminal.