$ git clone -n https://src.fedoraproject.org/rpms/nbdkit.git /var/lib/mock/f41-build-843458-162047/root/chroot_tmpdir/scmroot/nbdkit
Cloning into '/var/lib/mock/f41-build-843458-162047/root/chroot_tmpdir/scmroot/nbdkit'...
$ git fetch origin c25e90d6e461dd87bae916550ecb27fc54b47181:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/nbdkit
 * [new ref]         c25e90d6e461dd87bae916550ecb27fc54b47181 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c25e90d New upstream stable branch version 1.40.1