Should be fixed now. The Google End-to-End library uses the 5-byte encoding scheme for signature subpacket lengths, which I hadn't seen used before and was buggy in KBPGP. Most signature subpackets are <192 bytes long and can be encoded with the 2-byte length encoding.

BTW, our library doesn't support the ECC extensions yet, so any encryptions/signatures generated with ECC keys will fail to decrypt/verify on keybase (and also on GPG v1.4).