Lima fails with white screen in master. 19.1 is ok

In sailfish on the pinephone, we are using lima 19.1.4 relatively successfully. However, when updating to a more recent version in a hope to fix various rendering issues, we hit a problem.

To simplify, I built kmscube to test the mesa install.

Running kmscube with master results in a white screen.

I bisected over about 8 hours (!) and found the culprit to be this commit: mesa/mesa@cf1ab4b9

I double checked the previous commit which shows kmscube ok: mesa/mesa@443c5a3c

Userspace is 32bit, and compiler is gcc version 4.9.4 20160726 (Mer 4.9.4-1) (Linaro GCC 4.9-2017.01)