$ git clone -n https://src.fedoraproject.org/rpms/nbdkit.git /var/lib/mock/f40-build-2541570-61877/root/chroot_tmpdir/scmroot/nbdkit
Cloning into '/var/lib/mock/f40-build-2541570-61877/root/chroot_tmpdir/scmroot/nbdkit'...
$ git fetch origin cd089e3429150193e1f3e4a1defe182affe51334:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nbdkit
 * [new ref]         cd089e3429150193e1f3e4a1defe182affe51334 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cd089e3 New upstream development version 1.37.11