You have to import the fsfla key. $ wget http://linux-libre.fsfla.org/pub/linux-libre/rt/archive-key.asc
$ sudo apt-key add archive-key.asc $ sudo apt-get update $ sudo apt-get install linux-libre-rt
You have to import the fsfla key. $ wget http://linux-libre.fsfla.org/pub/linux-libre/rt/archive-key.asc
$ sudo apt-key add archive-key.asc $ sudo apt-get update $ sudo apt-get install linux-libre-rt