Ubuntu Apt-get Update Error Resolution

It is very convenient to install the development software with the Apt-get command, but for various reasons, often the software source is not linked, so you need to use the sudo apt-get Update command to update the software source.

And the house leaks in the rain overnight, this time the update order also strikes, there are various errors ...

The following two errors occurred while executing sudo apt-get update.

W:GPG error:http://cran.cnr.berkeley.edu precise/release:the following signatures couldn ' t be verified because the pub Lic key is not Available:no_pubkey 51716619E084DAB9

W:GPG error:http://ppa.launchpad.net precise release:the following signatures were Invalid:badsig 1E9377A2BA9EF27F Lau Nchpad Toolchain Builds

Workaround:

The first one,

sudo apt-key adv--recv-keys--keyserver keyserver.ubuntu.com 51716619E084DAB9

The second one,

sudo apt-/var/lib/sudomvsudomkdir -P lists/sudo apt-sudo apt-get update

Ubuntu Apt-get Update Error Resolution