Disable parallel build, it seems to break the build due to scarce resources. Waf is heavy like that, I've had to do it in other waf-based projects too. It could probably work with -j2, though, but I thought I'd stay on the safe side.
I triggered a rebuild a few times and it hasn't failed since the change. Hope it fixes.

PS: Added the changes entry (forwarded request 113127 from klaussfreire) (forwarded request 113129 from dimstar)