testexport class is broken after the integration of python3 branch into master.
Sent patch to the mailing list: http://lists.openembedded.org/pipermail/openembedded-core/2016-June/122409.html
This has been solved with commit: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=91a7f54e088693b77cf91b886904cd56b80d7ff7