$ git clone -n https://src.fedoraproject.org/rpms/webkitgtk.git /var/lib/mock/f45-build-46519-838/root/chroot_tmpdir/scmroot/webkitgtk
Cloning into '/var/lib/mock/f45-build-46519-838/root/chroot_tmpdir/scmroot/webkitgtk'...
$ git fetch origin 10502942c497b7317a3bc27f57a02f4b94cc8944:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/webkitgtk
 * [new ref]         10502942c497b7317a3bc27f57a02f4b94cc8944 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1050294 Rebuilt for libxml2-2.15.4 (again)