$ git clone -n https://src.fedoraproject.org/rpms/rubygem-fog-libvirt.git /var/lib/mock/f39-build-1752829-41468/root/chroot_tmpdir/scmroot/rubygem-fog-libvirt
Cloning into '/var/lib/mock/f39-build-1752829-41468/root/chroot_tmpdir/scmroot/rubygem-fog-libvirt'...
$ git fetch origin 78719a52df2c1206462a248f361c2c8128647bf0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-fog-libvirt
 * [new ref]         78719a52df2c1206462a248f361c2c8128647bf0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 78719a5 Fix Minitest 5.19+ compatibility.