$ git clone -n https://src.fedoraproject.org/rpms/gnome-shell.git /var/lib/mock/f42-build-888006-188518/root/chroot_tmpdir/scmroot/gnome-shell
Cloning into '/var/lib/mock/f42-build-888006-188518/root/chroot_tmpdir/scmroot/gnome-shell'...
$ git fetch origin ea94aaf836ac39f75e97ddb27bf145f3941266bf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-shell
 * [new ref]         ea94aaf836ac39f75e97ddb27bf145f3941266bf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ea94aaf Backport MRs #3607 and 3609 to fix up issues in Utilities