INFO: mock.py version 2.0 starting (python version = 3.7.6)...
Start(bootstrap): init plugins
INFO: tmpfs initialized
INFO: selinux disabled
Finish(bootstrap): init plugins
Start: init plugins
INFO: tmpfs initialized
INFO: selinux disabled
Finish: init plugins
INFO: Signal handler active
Start: run
INFO: Start(/var/tmp/tnef/tnef-1.4.10-5.fc30.art.src.rpm)  Config(epel-7-x86_64)
Start: clean chroot
Finish: clean chroot
Start(bootstrap): chroot init
INFO: mounting tmpfs at /var/lib/mock/epel-7-x86_64-bootstrap/root.
INFO: calling preinit hooks
INFO: enabled root cache
INFO: enabled package manager cache
Start(bootstrap): cleaning package manager metadata
Finish(bootstrap): cleaning package manager metadata
INFO: enabled HW Info plugin
Mock Version: 2.0
INFO: Mock Version: 2.0
Start(bootstrap): dnf install
ERROR: Exception(/var/tmp/tnef/tnef-1.4.10-5.fc30.art.src.rpm) Config(epel-7-x86_64) 0 minutes 2 seconds
INFO: Results and/or logs in: /var/lib/mock/epel-7-x86_64/result
INFO: unmounting tmpfs.
ERROR: Command failed: 
 # /usr/bin/dnf --installroot /var/lib/mock/epel-7-x86_64-bootstrap/root/ --setopt=deltarpm=False --allowerasing --disableplugin=local --disableplugin=spacewalk install dnf dnf-plugins-core
Unable to detect release version (use '--releasever' to specify release version)
No matches found for the following disable plugin patterns: local, spacewalk
No match for argument: dnf
No match for argument: dnf-plugins-core
Error: Unable to find a match: dnf dnf-plugins-core