Description of problem:
I'm unable to install build dependencies of FreeIPA with dnf builddep any more.
The command fails because it cannot find a matching package for
/usr/lib/krb5/plugins/kdb/db2.so on X86_64. The path is wrong and should be
/usr/lib64, not /usr/lib. Both FreeIPA and KRB5 spec files use %{_libdir}. The
builddep command used to work a couple of weeks ago.

I suspect an infrastructure and tooling bug, perhaps in rpm or dnf?

Version-Release number of selected component (if applicable):
rpm-4.14.2.1-2.fc29.x86_64
dnf-4.2.5-3.fc29.noarch
krb5-server-1.16.1-25.fc29.x86_64
freeipa-server-4.7.3-2.fc29.x86_64

How reproducible:
always, on F29 and F30

Steps to Reproduce:
1. dnf builddep freeipa-server

Actual results:
No matching package to install: '/usr/lib/krb5/plugins/kdb/db2.so'
Not all dependencies satisfied
Error: Some packages could not be found.

Expected results:
command should work

Additional info:
$ uname -p
x86_64
$ rpm -qf /usr/lib64/krb5/plugins/kdb/db2.so
krb5-server-1.16.1-25.fc29.x86_64

spec files from dist git, F29 branch:
$ grep db2.so krb5.spec
%{_libdir}/krb5/plugins/kdb/db2.so
$ grep db2.so freeipa.spec
BuildRequires:  %{_libdir}/krb5/plugins/kdb/db2.so