osx -datadir does not work

[bumbacoin]

just noticed that the osx qt use of the datadir argument does not work,
it will only use default folder in /application support

open OKCash.app --args -datadir=/different/datadir/here

debug doesnt show anything useful
just mentions default directory is being used

OKCash version v4.0.0.1-g ()
Operating in full mode.
Using OpenSSL version OpenSSL 1.0.2h  3 May 2016
Startup time: 20/11/2016 13:55:17
Default data directory /Users/User/Library/Application Support/OKCash
Used data directory /Users/User/Library/Application Support/OKCash
dbenv.open LogDir=/Users/User/Library/Application Support/OKCash/database ErrorFile=/Users/User/Library/Application Support/OKCash/db.log