The make command seems to have spilled its address space with python calls and clones before the execve() to run make inside a subdirectory. I don't think we really have to investigate this much further. We can simply do all the python calls explicitly before the qom test suite by running "make tests/qom-test" before the "make check-report.html" call. Verifying whether it reproducibly fixes the build. If it does, I'll commit the change.