Description of problem:

I have,
$ rpm -q nss-pem
nss-pem-1.0.3-6.fc27.x86_64
nss-pem-1.0.3-6.fc27.i686

 
Version-Release number of selected component (if applicable):

nss-pem-1.0.3-6.fc27.i686

Actual results:

I get error like this,

Error: 
 Problem: nss-pem-1.0.3-6.fc27.i686 has inferior architecture
  - nss-pem-1.0.3-6.fc27.x86_64 does not belong to a distupgrade repository
  - problem with installed package nss-pem-1.0.3-6.fc27.i686

Additional info:

$ dnf repoquery --releasever 28 nss-pem
nss-pem-0:1.0.3-9.fc28.x86_64

Seems like i686 package is missing.

Same problem was there for f26,
https://bugzilla.redhat.com/show_bug.cgi?id=1500655