When I try to compile lyx-1.3.4 using my CFLAGS="-march=pentium3 -pipe -Os -force-address -fomit-frame-pointer" emerge fail returning an error like "out of memory" but using CFLAGS="-march=pentium3 -pipe" all works well. Probably ebuild need to filter some CFLAGS Reproducible: Always Steps to Reproduce: 1. 2. 3.
If you have time could you track down what flags are actually causeing your build failure?
The same CFLAGS doesn't fail here.... It seems it is related to the amount of memory you have, and it depends on you which flag is causing the problem. If you find specific flag making the error, feel free to reopen and I'll filter it from lyx ebuild.