https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66203
--- Comment #4 from Richard Earnshaw <rearnsha at gcc dot gnu.org> --- The Arm builds that do not need anything from libgloss (and thus do not need a specs file) while linking come from a configuration that hard codes the underlying runtime monitor (usually the arm semihosting ABI) directly into newlib. I understand that's deprecated and was not implemented for AArch64.
