globaldb:PRIMARY> db.o1_name_sharded.aggregate([{$group:{_id:"$source",c:{$sum:1}}}])
assert: command failed: {
	"_t" : "OKMongoResponse",
	"ok" : 0,
	"code" : 115,
	"errmsg" : "'$group' is not supported",
	"$err" : "'$group' is not supported"
} : aggregate failed
_getErrorWithCode@src/mongo/shell/utils.js:25:13
doassert@src/mongo/shell/assert.js:16:14
assert.commandWorked@src/mongo/shell/assert.js:370:5
DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1319:5
@(shell):1:1

2017-06-16T17:33:22.692+0000 E QUERY    [thread1] Error: command failed: {
	"_t" : "OKMongoResponse",
	"ok" : 0,
	"code" : 115,
	"errmsg" : "'$group' is not supported",
	"$err" : "'$group' is not supported"
} : aggregate failed :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
doassert@src/mongo/shell/assert.js:16:14
assert.commandWorked@src/mongo/shell/assert.js:370:5
DBCollection.prototype.aggregate@src/mongo/shell/collection.js:1319:5
@(shell):1:1