$ git clone -n https://src.fedoraproject.org/rpms/nbdkit.git /var/lib/mock/f39-build-2269148-54761/root/chroot_tmpdir/scmroot/nbdkit
Cloning into '/var/lib/mock/f39-build-2269148-54761/root/chroot_tmpdir/scmroot/nbdkit'...
$ git fetch origin c2db7b231a83d68f570c87e5716485ef901d58a1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nbdkit
 * [new ref]         c2db7b231a83d68f570c87e5716485ef901d58a1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c2db7b2 New upstream stable version 1.36.3