$ git clone -n https://src.fedoraproject.org/rpms/R-DelayedArray.git /var/lib/mock/f38-build-724219-99404/root/chroot_tmpdir/scmroot/R-DelayedArray
Cloning into '/var/lib/mock/f38-build-724219-99404/root/chroot_tmpdir/scmroot/R-DelayedArray'...
$ git fetch origin 8bf52ac0e14694f1bdebc4f40444182ade8b0cc0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-DelayedArray
 * [new ref]         8bf52ac0e14694f1bdebc4f40444182ade8b0cc0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8bf52ac R-maint-sig mass rebuild