Export Sanitizer Fixes, master branch (2019.12.09.)

Let's try this once again...

This is a continuation from !572 (merged) and !575 (merged). Hopefully this time around I finally managed to crack the code on how to make the external projects more robust against build failures.

To make sure, this time around I'll have a careful look at the build directory of both this MR and the one going into atlas/athena before anything would be merged in...

Let's tag ATLINFR-3221 on this MR as well.