experimental-9.0-20241016 fails to build when modifying build flags

[roadapathy]

experimental-9.0-20241016

If I modify this part of the Makefile.in in any small way at all then the build breaks. For example, if I change nocona to native then it breaks.
OPTIMIZE_FLAGS := -O2 -march=nocona -mtune=core-avx2 -mfpmath=sse

I removed the -Werror here so that it won't stop at warnings.
WINE_CONFIGURE_ARGS =
--with-mingw
--disable-tests

I created some log files using which I will include:
make redist > output.log 2>&1

I have been modifying 9.03c and earlier versions without any issues:
OPTIMIZE_FLAGS := -O3 -march=native
and I have used:
OPTIMIZE_FLAGS := -O3 -march=native -flto

Yes, I understand this probably won't build a faster binary but it's for educational purposes and I'm learning a lot.

output.log

[roadapathy]

These are the projects that did not build:

[Sinfolke]

i would say not to use -O3 and remain -O2