Whenever I do 'M-x version', I see version number + ARCH + unknown-linux-gnu.

       GNU Emacs 25.0.92.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.18.7) of 2016-03-14

What causes it to print 'unknown', can it be replaced with something more meaningful..Say, a distro name?

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