$ git clone -n https://src.fedoraproject.org/rpms/R-GenomeInfoDb.git /var/lib/mock/f43-build-58895317-6569073/root/chroot_tmpdir/scmroot/R-GenomeInfoDb
Cloning into '/var/lib/mock/f43-build-58895317-6569073/root/chroot_tmpdir/scmroot/R-GenomeInfoDb'...
$ git fetch origin e16193be610ed7ba7ffbf9665d9514aebd702f75:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-GenomeInfoDb
 * [new ref]         e16193be610ed7ba7ffbf9665d9514aebd702f75 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e16193b R-maint-sig mass rebuild