my ~/.mozconfig, for those interested:
ac_add_options --enable-mathml
ac_add_options --enable-svg
ac_add_options --enable-new-cache
ac_add_options --enable-libpr0n
ac_add_options --enable-optimize=-O2
ac_add_options --disable-debug
ac_add_options --enable-strip-libs
this should also test my reiser partition... it was reported on the LKML that mozilla wouldn't build because of reiserfs corruption (but would on the same system on an ext2 partition), but that's supposed to be fixed now. we'll see. ;-)