Test hasn't changed significantly in the meantime. Results in this error:

{
"ok" : 0,
"errmsg" : "MR parallel processing failed:

{ assertion: \"couldn't compile code for: _map\", assertionCode: 13598, errmsg: \"db assertion failure\", ok: 0.0 }

"
}
{
"assertion" : "couldn't compile code for: _map",
"assertionCode" : 13598,
"errmsg" : "db assertion failure",
"ok" : 0
}