$ git clone -n https://src.fedoraproject.org/rpms/nbdkit.git /var/lib/mock/f39-build-1700793-41200/root/chroot_tmpdir/scmroot/nbdkit
Cloning into '/var/lib/mock/f39-build-1700793-41200/root/chroot_tmpdir/scmroot/nbdkit'...
$ git fetch origin 8e4e221f2f97f95d0f590315ef35a868755a0482:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nbdkit
 * [new ref]         8e4e221f2f97f95d0f590315ef35a868755a0482 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8e4e221 New upstream stable version 1.36.1