Installing R from CRAN Ubuntu repository: No Public Key Error

Question

I am on R version 2.13 and would like to update to a newer version in order to use some packages that depend on R>= 2.14.

I have the line to my sources.list file as

Answer 1

The simplest solution that worked for me was from Emre Sahin in this thread:

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

Answer 2

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys KEYID

and replace KEYID with the number shown in the error message.

Answer 3

Here is a step-by-step answer that might be easier to follow.

1. Fetch the key (the last 8 digits in the warning message):

   gpg --keyserver pgp.mit.edu --recv-key E084DAB9
   

   The output should look like this:

   gpg: requesting key E084DAB9 from hkp server pgp.mit.edu
   gpg: key E084DAB9: public key "Michael Rutter <marutter@gmail.com>" imported
   gpg: Total number processed: 1
   gpg:               imported: 1  (RSA: 1)
   

2. Add the key (superuser access required):

   gpg -a --export E084DAB9 | sudo apt-key add -
   

3. Update the repositories:

   sudo apt-get update
   

There should be no warning about the missing key now.