When I try to run launchpad-getkeys, I get HTTP Error 7:
gpg: requesting key BB901940 from hkp server keyserver.ubuntu.com
?: keyserver.ubuntu.com: Host not found
gpgkeys: HTTP fetch error 7: couldn't connect: Success
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
But this does work:
root@Lenovo-Z580:/etc/apt# launchpad-getkeys -k

Please wait... launchpad-getkeys is running an update so 
it can detect the missing GPG keys

Trying to import all the missing keys
gpg: requesting key BB901940 from hkp server
gpg: key BB901940: public key "Launchpad Daily Build" imported
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)
Here is the IP address of keyserver.ubuntu.com.

Of course, this shouldn't be necessary. The problem seems to lie in how launchpad-ketkeys resolves the URL of its keyserver. BUG!!!