$ git clone -n https://src.fedoraproject.org/rpms/R-Rcpp.git /var/lib/mock/f42-build-side-1-3584168-46892/root/chroot_tmpdir/scmroot/R-Rcpp
Cloning into '/var/lib/mock/f42-build-side-1-3584168-46892/root/chroot_tmpdir/scmroot/R-Rcpp'...
$ git fetch origin 1a0e862854e70a2263d542c36c47e7ebab743d69:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-Rcpp
 * [new ref]         1a0e862854e70a2263d542c36c47e7ebab743d69 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1a0e862 Update to 1.1.0