$ git clone -n https://src.fedoraproject.org/rpms/rust-gdk-pixbuf-sys0.19.git /var/lib/mock/f42-build-side-1-3504282-45983/root/chroot_tmpdir/scmroot/rust-gdk-pixbuf-sys0.19
Cloning into '/var/lib/mock/f42-build-side-1-3504282-45983/root/chroot_tmpdir/scmroot/rust-gdk-pixbuf-sys0.19'...
$ git fetch origin a77fe217072284dd4b876ef6f9be3b132388ce06:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gdk-pixbuf-sys0.19
 * [new ref]         a77fe217072284dd4b876ef6f9be3b132388ce06 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a77fe21 compat package no longer needed