$ git clone -n https://src.fedoraproject.org/rpms/R-here.git /var/lib/mock/f40-build-1944462-25177/root/chroot_tmpdir/scmroot/R-here
Cloning into '/var/lib/mock/f40-build-1944462-25177/root/chroot_tmpdir/scmroot/R-here'...
$ git fetch origin 8177eb125ce80ecfa496a1d22c5b3a5f9eaf3d6e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-here
 * [new ref]         8177eb125ce80ecfa496a1d22c5b3a5f9eaf3d6e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8177eb1 R-maint-sig mass rebuild