$ git clone -n https://src.fedoraproject.org/rpms/libnbd.git /var/lib/mock/f41-build-1266697-23069/root/chroot_tmpdir/scmroot/libnbd
Cloning into '/var/lib/mock/f41-build-1266697-23069/root/chroot_tmpdir/scmroot/libnbd'...
$ git fetch origin 9cd593e56501d3fae46295d16d235747aebae096:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libnbd
 * [new ref]         9cd593e56501d3fae46295d16d235747aebae096 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9cd593e New upstream development version 1.21.1