With binaries, there are some cases need un-extracted packages (e.g. rpm) to be exported as well. Case need do rpm install and check if it works or not.
I'll take this one. I would like to add that a good extension of this feature would be to be able to take .rpm files from build machine and use them for tests written after the testing environment has been installed on a remote machine. This will allow the test environment to be exported only once and be used as stand alone after (no need to do the steps associated to creating the involved tarballs on the build machine)
this should add the needed functionality: http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/log/?h=cc-tin/YP7850_final Please use the latest hash
Sent patches to the mailing list: http://lists.openembedded.org/pipermail/openembedded-core/2016-May/121992.html
This has been implemented in: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=d56ccf691b194ce4d753b2bd1a4b12c524d4a887