Dan Horák wrote:
We are going to change the default -mcpu for s390(x) from the
-mcpu=z9-109 to -mcpu=z10. z10 is the minimum level various projects
require - llvm/clang, OCaml, pypy3, ... Unfortunately we can't go
higher because our community guest VM is still running on a z10 machine.
z10 is supported, officially, until 2019-2020: