So so …
W: GPG error: [your favourite mirror here] Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 010908312D230C5F
W: You may want to run apt-get update to correct these problems
Ever met this is last days?
The solution is simple, but not well documented well:
you must add these keys manually (as root or using sudo):
gpg --recv-keys 07DC563D1F41B907 && gpg --export 07DC563D1F41B907 | sudo apt-key add -
gpg --recv-keys 010908312D230C5F && gpg --export 010908312D230C5F | sudo apt-key add -
or in the case you do no use GnuPG
wget http://ftp-master.debian.org/ziyi_key_2006.asc -O - | sudo apt-key add -
That’s all.