$ repoquery --repo=compose --requires koji-builder | grep python
/usr/bin/python2
/usr/bin/python3
python3-cheetah
python3-koji = 1.17.0-6.fc31
python3-librepo
python3-multilib

$ repoquery --repo=compose koji-builder
koji-builder-0:1.17.0-6.fc31.noarch

$ head -n1 /usr/libexec/kojid/mergerepos
#!/usr/bin/python2


$ grep import /usr/libexec/kojid/mergerepos
from __future__ import absolute_import
import createrepo
import os.path
import rpmUtils.miscutils
import shutil
import sys
import tempfile
import yum
import yum.misc
from optparse import OptionParser


This file cannot work without python2-createrepo and python2-yum. Since that, the dependency solely on /usr/bin/python2 is useles and this file should be excluded form the package, or kept without executable permission, or if absolutely desired to be kept as is, the dependency shall be filtered out.