The changes in bug #296917 break chromium compilation on non-multilib 'mixed' systems (like my 64 bit kernel, 32 bit userland system) and cross-compilation on 'standard' systems. Both '[[ $ABI = XXX ]]' conditions are always evaluated as false; as a consequence some components of chromium (V8 for example) get the wrong arch (from 'uname', I suppose) and don't use the correct target causing a build failure.
Sigh indeed it messed cross-compiling... Let me check a few things and I'll revert this ASAP
Reverted to "use $arch" (as it's done for arm now already), thanks for the report