$ git clone -n https://src.fedoraproject.org/rpms/perl-Mock-Config.git /var/lib/mock/f45-build-24757-606/root/chroot_tmpdir/scmroot/perl-Mock-Config
Cloning into '/var/lib/mock/f45-build-24757-606/root/chroot_tmpdir/scmroot/perl-Mock-Config'...
$ git fetch origin c179564fecae6188d7445f7f270a90f7934cbbda:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/perl-Mock-Config
 * [new ref]         c179564fecae6188d7445f7f270a90f7934cbbda -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c179564 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild