ubuntu@cx1640-1:~$ sudo apt-get build-dep stress-ng
Reading package lists... Done
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 103 not upgraded.
ubuntu@cx1640-1:~$ sudo apt-get -b source -t zesty stress-ng
Reading package lists... Done
E: The value 'zesty' is invalid for APT::Default-Release as such a release is not available in the sources
E: Unable to find a source package for