$ git clone -n https://src.fedoraproject.org/rpms/R-BiocParallel.git /var/lib/mock/f42-build-side-1-3501735-45976/root/chroot_tmpdir/scmroot/R-BiocParallel
Cloning into '/var/lib/mock/f42-build-side-1-3501735-45976/root/chroot_tmpdir/scmroot/R-BiocParallel'...
$ git fetch origin 07981d391c7136261de05752c8647f9fb9351b90:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-BiocParallel
 * [new ref]         07981d391c7136261de05752c8647f9fb9351b90 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 07981d3 R-maint-sig mass rebuild