cannot perform order operation for aggregate functions

to reproduce

./testrunner -i /tmp/tuqvm.ini doc-per-day=6,standard_buckets=1,skip_build_tuq=True,cbq_version=sherlock,get-cbcollect-info=True,services_init=kv:index:n1ql -t tuqquery.newtuq.QueryTests.test_order_by_aggr_fn,GROUP=ORDER;P0

query is SELECT email AS TITLE FROM default GROUP BY email ORDER BY MIN(join_day), email

the error is
{
"requestID": "9eae28bf-7830-406c-a8a0-054c173861b0",
"errors": [

{ "code": 4000, "msg": "Aggregates not available for this ORDER BY." }

],
"status": "fatal",
"metrics":

{ "elapsedTime": "1.454869ms", "executionTime": "1.286026ms", "resultCount": 0, "resultSize": 0, "errorCount": 1 }

}