$ git clone -n https://src.fedoraproject.org/rpms/gwenhywfar.git /var/lib/mock/f39-build-1491856-34522/root/chroot_tmpdir/scmroot/gwenhywfar
Cloning into '/var/lib/mock/f39-build-1491856-34522/root/chroot_tmpdir/scmroot/gwenhywfar'...
$ git fetch origin a1baff5684847bea717f20390b8cf0d4758875f0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gwenhywfar
 * [new ref]         a1baff5684847bea717f20390b8cf0d4758875f0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a1baff5 Fix flatpak build