Description of problem:
running a repolist of dnf/yum command with debug level 6 and above results in a python attribute error :

[stack@undercloud-0 ~]$ dnf -d 6 repolist                                                                                                                                                                                                     
Loaded plugins: builddep, changelog, config-manager, copr, debug, debuginfo-install, download, generate_completion_cache, needs-restarting, playground, repoclosure, repodiff, repograph, repomanage, reposync, uploadprofile
DNF version: 4.2.17
cachedir: /var/tmp/dnf-stack-q4ir25e8
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/python3.6/site-packages/dnf/cli/main.py", line 191, in user_main
    errcode = main(args)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 65, in main
    return _main(base, args, cli_class, option_parser_class)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 98, in _main
    return cli_run(cli, base)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 114, in cli_run
    cli.run()
  File "/usr/lib/python3.6/site-packages/dnf/cli/cli.py", line 1160, in run
    return self.command.run()
  File "/usr/lib/python3.6/site-packages/dnf/cli/commands/repolist.py", line 146, in run
    ui_size = _repo_size(self.base.sack, repo)
  File "/usr/lib/python3.6/site-packages/dnf/cli/commands/repolist.py", line 65, in _repo_size
    for pkg in sack.query(flags=hawkey.IGNORE_EXCLUDES).filterm(reponame__eq=repo.id):
AttributeError: 'NoneType' object has no attribute 'query'


the problem doesn't exist when running 'dnf repolist' or 'dnf -d X repolist' where X is 5 or less

Version-Release number of selected component (if applicable):
[stack@undercloud-0 ~]$ cat /etc/*release
NAME="Red Hat Enterprise Linux"
VERSION="8.2 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.2"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.2 Beta (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8.2:beta"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.2
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.2 Beta"
Red Hat Enterprise Linux release 8.2 Beta (Ootpa)
Red Hat Enterprise Linux release 8.2 Beta (Ootpa)

RHEL taken from:
http://download.devel.redhat.com/brewroot/packages/rhel-guest-image/8.2/220/images/rhel-guest-image-8.2-220.x86_64.qcow2


stack@undercloud-0 ~]$ dnf list installed | grep -i dnf
dnf.noarch                                    4.2.17-6.el8                              @anaconda       
dnf-data.noarch                               4.2.17-6.el8                              @anaconda       
dnf-plugin-spacewalk.noarch                   2.8.5-11.module+el8.1.0+3455+3ddf2832     @koji-override-1
dnf-plugin-subscription-manager.x86_64        1.26.14-1.el8                             @anaconda       
dnf-plugins-core.noarch                       4.0.12-3.el8                              @anaconda       
libdnf.x86_64                                 0.39.1-5.el8                              @anaconda       
python3-dnf.noarch                            4.2.17-6.el8                              @anaconda       
python3-dnf-plugin-spacewalk.noarch           2.8.5-11.module+el8.1.0+3455+3ddf2832     @koji-override-1
python3-dnf-plugins-core.noarch               4.0.12-3.el8                              @anaconda       
python3-libdnf.x86_64                         0.39.1-5.el8                              @anaconda       


[stack@undercloud-0 ~]$ dnf --version
4.2.17
  Installed: dnf-0:4.2.17-6.el8.noarch at Tue 10 Mar 2020 01:38:06 PM GMT
  Built    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla> at Tue 18 Feb 2020 01:20:38 PM GMT

  Installed: rpm-0:4.14.2-37.el8.x86_64 at Tue 10 Mar 2020 01:37:10 PM GMT
  Built    : Red Hat, Inc. <http://bugzilla.redhat.com/bugzilla> at Fri 21 Feb 2020 01:46:44 PM GMT


The issue appears in our all our OSP CI 16.1+rhel8.2 jobs.
I haven't been tested with plain rhel build.

Tried 'dnf update -y' and then the 'dnf -d 6 repolist' = failure again

How reproducible:
100%


Steps to Reproduce:
1. bootup rhel8.2
2. run 'dnf -d 6 repolist'
3.

Actual results:
failure

Expected results:
success

Additional info:
I have a machine stacked with this rhel8.2 dnf issue at the moment, ping me on irc (nick: wznoinsk) if you wnat to troubleshoot the problem there