Code:
Dec 08 14:08:10 fedora systemd-logind[841]: System is rebooting.
Dec 08 14:08:10 fedora systemd[1]: Starting System Upgrade using DNF failed...
Dec 08 14:08:10 fedora kernel: audit: type=1130 audit(96): pid=1 uid=0 auid=95 ses=95 msg='unit=dnf-system-upgrade comm="systemd" exe="/usr/lib>
Dec 08 14:08:10 fedora audit[1]: SERVICE_START pid=1 uid=0 auid=95 ses=95 msg='unit=dnf-system-upgrade comm="systemd" exe="/usr/lib/systemd/systemd" hostname=>
Dec 08 14:08:10 fedora systemd[1]: dnf-system-upgrade.service: Triggering OnFailure= dependencies.
Dec 08 14:08:10 fedora systemd[1]: Failed to start System Upgrade using DNF.
Dec 08 14:08:10 fedora systemd[1]: dnf-system-upgrade.service: Failed with result 'exit-code'.
Dec 08 14:08:10 fedora systemd[1]: dnf-system-upgrade.service: Main process exited, code=exited, status=1/FAILURE
Dec 08 14:08:10 fedora dnf[739]: ValueError: invalid null reference in method 'new_VectorString', argument 1 of type 'std::vector< std::string > const &'
Dec 08 14:08:10 fedora dnf[739]:     this = _conf.new_VectorString(*args)
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib64/python3.7/site-packages/libdnf/conf.py", line 1225, in __init__
Dec 08 14:08:10 fedora dnf[739]:     self.base.conf.exclude = libdnf.conf.VectorString(self.state.exclude)
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf-plugins/system_upgrade.py", line 395, in configure_upgrade
Dec 08 14:08:10 fedora dnf[739]:     subfunc()
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf-plugins/system_upgrade.py", line 332, in _call_sub
Dec 08 14:08:10 fedora dnf[739]:     self._call_sub("configure")
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf-plugins/system_upgrade.py", line 320, in configure
Dec 08 14:08:10 fedora dnf[739]:     self.command.configure()
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf/cli/cli.py", line 914, in configure
Dec 08 14:08:10 fedora dnf[739]:     cli.configure(list(map(ucd, args)), option_parser())
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf/cli/main.py", line 95, in _main
Dec 08 14:08:10 fedora dnf[739]:     return _main(base, args, cli_class, option_parser_class)
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf/cli/main.py", line 64, in main
Dec 08 14:08:10 fedora dnf[739]:     errcode = main(args)
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/lib/python3.7/site-packages/dnf/cli/main.py", line 179, in user_main
Dec 08 14:08:10 fedora dnf[739]:     main.user_main(sys.argv[1:], exit_code=True)
Dec 08 14:08:10 fedora dnf[739]:   File "/usr/bin/dnf", line 58, in <module>
Dec 08 14:08:10 fedora dnf[739]: Traceback (most recent call last):
Dec 08 14:08:10 fedora python3[739]: error sending data to ABRT daemon: 
Dec 08 14:08:10 fedora python3[739]: can't communicate with ABRT daemon, is it running? [Errno 2] No such file or directory
Dec 08 14:08:10 fedora pk-offline-update[738]: percentage 8%
Dec 08 14:08:10 fedora python3[739]: detected unhandled Python exception in '/usr/bin/dnf'
Dec 08 14:08:10 fedora pk-offline-update[738]: percentage 7%
Dec 08 14:08:10 fedora pk-offline-update[738]: status loading-cache
Dec 08 14:08:10 fedora pk-offline-update[738]: percentage 6%
Dec 08 14:08:10 fedora packagekitd[751]: Skipping refresh of bumblebee: cannot update repo 'bumblebee': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All m>
Dec 08 14:08:09 fedora pk-offline-update[738]: status download-repository
Dec 08 14:08:07 fedora pk-offline-update[738]: percentage 5%
Dec 08 14:08:06 fedora pk-offline-update[738]: percentage 4%
Dec 08 14:08:06 fedora pk-offline-update[738]: percentage 3%
Dec 08 14:08:06 fedora pk-offline-update[738]: percentage 2%
Dec 08 14:08:06 fedora pk-offline-update[738]: percentage 1%
Dec 08 14:08:05 fedora pk-offline-update[738]: status loading-cache
Dec 08 14:08:05 fedora pk-offline-update[738]: percentage 0%
Dec 08 14:08:05 fedora pk-offline-update[738]: status query
Dec 08 14:08:05 fedora pk-offline-update[738]: status setup
Any idea pls ?