$ git clone -n https://src.fedoraproject.org/rpms/nbdkit.git /var/lib/mock/f41-build-815189-149424/root/chroot_tmpdir/scmroot/nbdkit
Cloning into '/var/lib/mock/f41-build-815189-149424/root/chroot_tmpdir/scmroot/nbdkit'...
$ git fetch origin 9ece3dd175a962b330a9ea0e1afd0955f769bc23:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nbdkit
 * [new ref]         9ece3dd175a962b330a9ea0e1afd0955f769bc23 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9ece3dd New upstream development version 1.39.9