Description of problem:
"dnf repoquery --unsatisfied" caused this failure.

Version-Release number of selected component:
dnf-2.0.0-0.rc1.4.fc26

Additional info:
reporter:       libreport-2.8.0
cmdline:        /usr/libexec/system-python /usr/bin/dnf repoquery --unsatisfied
executable:     /usr/bin/dnf
kernel:         4.8.8-300.fc25.x86_64
pkg_fingerprint: 812A 6B4B 64DA B85D
pkg_vendor:     Fedora Project
runlevel:       N 5
type:           Python3
uid:            0

Truncated backtrace:
repoquery.py:277:run:AttributeError: module 'dnf.sack' has no attribute 'rpmdb_sack'

Traceback (most recent call last):
  File "/usr/bin/dnf", line 58, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python3.5/site-packages/dnf/cli/main.py", line 170, in user_main
    errcode = main(args)
  File "/usr/lib/python3.5/site-packages/dnf/cli/main.py", line 60, in main
    return _main(base, args)
  File "/usr/lib/python3.5/site-packages/dnf/cli/main.py", line 111, in _main
    cli.run()
  File "/usr/lib/python3.5/site-packages/dnf/cli/cli.py", line 947, in run
    return self.command.run()
  File "/usr/lib/python3.5/site-packages/dnf/cli/commands/repoquery.py", line 277, in run
    rpmdb = dnf.sack.rpmdb_sack(self.base)
AttributeError: module 'dnf.sack' has no attribute 'rpmdb_sack'

Local variables in innermost frame:
q: <dnf.query.Query object at 0x7fa52071dfc0>
self: <dnf.cli.commands.repoquery.RepoQueryCommand object at 0x7fa520814f28>