https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78140
--- Comment #7 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- BTW Firefox trunk fails to build for me: ld: error: /tmp/ccsbLieS.ltrans29.ltrans.o: requires dynamic R_X86_64_PC32 reloc against '_ZN2js3jitL2R0E' which may overflow at runtime; recompile with -fPIC ld: error: read-only segment has dynamic relocations /tmp/ccsbLieS.ltrans29.ltrans.o:<artificial>:function js::jit::BaselineCompiler::emitCheckThis(js::jit::ValueOperand) [clone .constprop.20226]: error: undefined reference to 'js::jit::R0' Haven't looked into it yet. Could well be a Firefox bug.