I am putting together a chrooted installation of named and ran into a problem whereby attempting to generate an rndc.key with rndc-confgen just hangs, never returning and not generating a key.
After doing some searching I discovered that I needed to run the command as follows:
rndc-confgen -a -r /dev/urandom -t /var/named/chroot
Which outputs the following, generating the key file that I expected.
wrote key file "/etc/rndc.key"
wrote key file "/var/named/chroot/etc/rndc.key"