Following the RFC on this mailing list, the baseline ISA of the s390x
port has been raised z196. This allows Debian to support packages like
rust, go or nodejs, which do not support older ISAs. For now only this
packages are affected, but in the future the default ISA in GCC will
also be raised, so more and more packages will use the corresponding
As a consequence people should not upgrade to buster or sid if they have
and older CPU. The change does not affect Stretch, which will still be
supported for a bit more than 2 years.