> # ./xz < /dev/zero > /dev/null > Illegal instruction (core dumped) > CPU: Intel(R) Core(TM) i3 CPU 540 @ 3.07GHz (3059.08-MHz K8-class > CPU) > Origin="GenuineIntel" Id=0x20655 Family=0x6 Model=0x25 Stepping=5 > CPUTYPE?=westmere
It's liblzma, and it doesn't want westmere, it apparently wants penryn.