$ git clone -n https://src.fedoraproject.org/rpms/imsprog.git /var/lib/mock/f42-build-side-1-3540415-46574/root/chroot_tmpdir/scmroot/imsprog
Cloning into '/var/lib/mock/f42-build-side-1-3540415-46574/root/chroot_tmpdir/scmroot/imsprog'...
$ git fetch origin 6e7c0152a0c7442020ff95e0ea142cf516edce98:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/imsprog
 * [new ref]         6e7c0152a0c7442020ff95e0ea142cf516edce98 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e7c015 new version