$ git clone -n https://src.fedoraproject.org/rpms/R-Biostrings.git /var/lib/mock/f38-build-724197-99404/root/chroot_tmpdir/scmroot/R-Biostrings
Cloning into '/var/lib/mock/f38-build-724197-99404/root/chroot_tmpdir/scmroot/R-Biostrings'...
$ git fetch origin 11948da3daf581752fc72f0727e0aab13938061c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-Biostrings
 * [new ref]         11948da3daf581752fc72f0727e0aab13938061c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 11948da R-maint-sig mass rebuild