$ git clone -n https://src.fedoraproject.org/rpms/nbdkit.git /var/lib/mock/f40-build-795772-140317/root/chroot_tmpdir/scmroot/nbdkit
Cloning into '/var/lib/mock/f40-build-795772-140317/root/chroot_tmpdir/scmroot/nbdkit'...
$ git fetch origin 30394d37b4ea077ab4de49ee78749e4e1578c518:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nbdkit
 * [new ref]         30394d37b4ea077ab4de49ee78749e4e1578c518 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 30394d3 New upstream development version 1.37.9