Desculpe, acho que encontrei a resposta: link .
(citação começar)
Illegal Instruction errors on Squid 3.4
Synopsis Squid 3.4 and later, running on certain paravirtualized systems and even some claiming full virtualization (at least KVM, Xen, and Xen derivatives are confirmed so far) crashes with an illegal instruction error soon after startup.
Symptoms
Squid crashes with Illegal Instruction error immediately after startup on a virtual machine on Intel-compatible processors
Explanation
The Squid build system uses by default the
-march=native
gcc option to optimize the resulting binary. Unfortunately certain (para-)virtualization systems don't support the whole instruction set they advertise. The compiler doesn't know, and generates instructions which trigger this error.Workaround
These optimizations are helpful but not necessary to have a fully functional squid, especially on ia64/amd64 platforms. The detected defaults can be overridden by supplying the
--disable-arch-native
option to the configure script.
(fim da citação)
Estamos executando o Solaris dentro do VMware ESXi 6.0 . Então eu acho que essa é a razão.
Eu não vou deletar minha própria pergunta sobre a estranha chance de outra pessoa se deparar com isso também.