Bug#855401: ifupdown2 [1.0~git20170114-1~bpo8+1/jessie-backports] missing python-pkg-resources dependency

[Roopa Prabhu]

Thanks for reporting the issue. pkg_resources is only used to get the package 
version today.
We will most likely fix it by removing the use of pkg_resources given so little 
value it adds.

we will post a fix soon.

thanks.