$ git clone -n https://src.fedoraproject.org/rpms/rubygem-webkit2-gtk.git /var/lib/mock/f41-build-714898-13069/root/chroot_tmpdir/scmroot/rubygem-webkit2-gtk
Cloning into '/var/lib/mock/f41-build-714898-13069/root/chroot_tmpdir/scmroot/rubygem-webkit2-gtk'...
$ git fetch origin cebb3c7450709ac15f9f3ebb0a6022f075428ad6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-webkit2-gtk
 * [new ref]         cebb3c7450709ac15f9f3ebb0a6022f075428ad6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cebb3c7 4.2.2 entry