(xenial-backports/main amd64) Packages server certificate verification failed

Question

I tried to install gfortran by writing sudo apt-get install gfortran but the terminal simply showed

Enable to locate the packages for gfortran

So I again tried by writing

sudo apt-get update 

and it gives error.

Error is as shown below:

Err:65 http://archive.ubuntu.com/ubuntu xenial-backports/main amd64 Packages server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

Can anybody suggest what I should do?

Answer 1

apt-cache policy gfortran reveals that it is available in main Ubuntu repository. And since this error is about backport repository, you can safely ignore this. Proceed with

sudo apt-get install gfortran

To install the package.

Check this AU question to know about backport repository

• What are the differences between "precise" and "precise-updates" and "precise-backports"?