问题：
gpg: Signature made Ma 01 oct 2013 19:44:27 +0300 EEST using RSA key ID 692B382C
gpg: Can't check signature: public key not found
error: could not verify the tag 'v1.12.4'
gpg: Can't check signature: public key not found
error: could not verify the tag 'v1.12.4'
解决：
i found a solution here for the error that you are seeing : http://www.marshut.com/wrrts/repo-release-1-12-4.html
use the below command, this worked for me today.
curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
chmod a+x ~/bin/repo
use the below command, this worked for me today.
curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
chmod a+x ~/bin/repo