Can't verify avrdude-6.3.tar.gz

[hyperowl]

I downloaded avrdude-6.3.tar.gz and avrdude-6.3.tar.gz.sig from
https://download.savannah.gnu.org/releases/avrdude/, tried to verify and
got this:

gpg: assuming signed data in 'avrdude-6.3.tar.gz'
gpg: Signature made Tue 16 Feb 2016 10:02:43 PM UTC
gpg:                using DSA key F48CA81B69A85873
gpg: key F48CA81B69A85873: new key but contains no user ID - skipped
gpg: Total number processed: 1
gpg:           w/o user IDs: 1
gpg: Can't check signature: No public key

I also found https://github.com/facchinm/avrdude/releases but nothing
there is signed. What should I do now? It's important for me to build from
source and I'd much prefer it to be signed.