Unless I got lost in the package tree, I don't see any tests other than those in nixos/tests, which are effectively for the NixOS modules.

I want to start adding package tests, primarily for all those package I regularly update/maintain.

a) Where should I put those
b) How would I bootstrap them? (I want them to be run as part of the channel updates, not unlike the nixos/tests files)
c) Do we have concerns with Hydra build times if/when people were to start adding lots of tests?

/cc @vcunat @domenkozar @edolstra @shlevy @aszlig @fpletz @globin @joachifm @copumpkin @grahamc (just pinging people who usually have good opinions on these things, anybody is welcome to provide feedback)