$ git clone -n https://src.fedoraproject.org/rpms/gnome-shell-extension-caffeine.git /var/lib/mock/f40-build-2666619-67118/root/chroot_tmpdir/scmroot/gnome-shell-extension-caffeine
Cloning into '/var/lib/mock/f40-build-2666619-67118/root/chroot_tmpdir/scmroot/gnome-shell-extension-caffeine'...
$ git fetch origin fdbccc5f064ca389947e2d00aac293002ca5a689:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-shell-extension-caffeine
 * [new ref]         fdbccc5f064ca389947e2d00aac293002ca5a689 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fdbccc5 Forgot 53 sources