$ git clone -n https://src.fedoraproject.org/rpms/breeze-gtk.git /var/lib/mock/f42-build-3426865-45197/root/chroot_tmpdir/scmroot/breeze-gtk
Cloning into '/var/lib/mock/f42-build-3426865-45197/root/chroot_tmpdir/scmroot/breeze-gtk'...
$ git fetch origin 1c0eaecdad39e9f3274284067a0d7bb6ca940f45:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/breeze-gtk
 * [new ref]         1c0eaecdad39e9f3274284067a0d7bb6ca940f45 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1c0eaec 6.3.3