It doesn't seem to be the problem for compiler itself which also has %global rust_arches x86_64 i686 armv7hl aarch64 ppc64 ppc64le s390x, but it is non-noarch.

Either there was some conf change within last 9 days or there is long-standing bug somewhere.

[brain@ignatenko-w541 rust-packaging]$ koji mock-config --buildroot 10249690 | grep i386
config_opts['target_arch'] = 'i386'
config_opts['yum.conf'] = '[main]\ncachedir=/var/cache/yum\ndebuglevel=1\nlogfile=/var/log/yum.log\nreposdir=/dev/null\nretries=20\nobsoletes=1\ngpgcheck=0\nassumeyes=1\nkeepcache=1\ninstall_weak_deps=0\nstrict=1\n\n# repos\n\n[build]\nname=build\nbaseurl=https://kojipkgs.fedoraproject.org//repos/f28-build/801275/i386\n'
config_opts['macros']['%_host_cpu'] = 'i386'
config_opts['macros']['%_host'] = 'i386-koji-linux-gnu'

Seems that this is some misconfiguration because hw_info.log shows Architecture: i686

Looking at Rust build (from 9 days ago) it shows same about of i386 things in there. So I'm not sure where bug is because that build passed. I doubt it was due to different RPM version because in 4.14 there were no changes (which I am aware of) regarding handling architectures.

you should use %{ix86} and not hardcode i686, for noarch tasks koji will use the basearch which on 32 bit x86 is i386

you should use %{ix86} and not hardcode i686, for noarch tasks koji will use the basearch which on 32 bit x86 is i386

That's not entirely right. Rust doesn't compile on i386/i486/i586 but it compiles on i686. And in terms of RPM, ExcludeArch/ExclusiveArch is the arch, not basearch. So I still think it is some configuration issue or koji bug.

That's not entirely right. Rust doesn't compile on i386/i486/i586 but it compiles on i686. And in terms of RPM, ExcludeArch/ExclusiveArch is the arch, not basearch. So I still think it is some configuration issue or koji bug.

It is not something that is configurablein koji and it is also how koji has been designed to work, 32 bit x86 noarch builds will always be i386, you can ask the koji devs to special case your use case in koji, you can make the packages archful, or you can use %{ix86} for the arch macro.

Opened https://pagure.io/koji/issue/659. Let's keep this issue for tracking when fix will arrive in Fedora's koji deployment.

Since koji ticket is still open, cannot close this just yet.

Same status as https://pagure.io/koji/issue/659 remains open with no assignee.

From our grooming discussion on #fedora-releng channel on Apr 12 2019

proposal: close in favor of upstream issue (and point to it). If it changes somehow in koji we can adjust.