[yocto] Error running testimage under the autobuilder with pyro branch

[Alex Lennon]

Hi all,

I've got some simple automated testing going to test meta-mono 
core-image-mono builds.

It just bitbakes the image then runs the testimage command

This works fine for master and rocko branches, but I get a failure for pyro

     Exception: TypeError: Test oeRuntimeTest is not derived from 
OERuntimeTestCase

The rest of the log is here: https://pastebin.com/NRVLLtsF

Can anybody point me towards what might have changed between branches / 
where I'm going wrong?

Thanks,

Alex