DllNotFoundException at MonoPosixHelper when using System.IO.Ports on mac Standalone

Hi,
I've developed a plugin that enables the USB Serial communication on Android, and it worked fine.
Later I tried to implement the same functionality to work on the Unity Editor and Standalone builds.

The implemented code works as expected on the Editor, but when I build it for OS X standalone, it throws `DllNotFoundException : MonoPosixHelper` at System.IO.Ports.SerialPortStream : open_serial .

So I opened the built package, and confirmed that `libMonoPosixHelper.dylib` file is existing at `Contents/Frameworks/Mono/MonoEmbedRuntime/osx/`.

I had searched the Issue Tracker and found a similar issue that was occured back in Unity 5.4, but it was for OS X Editor issue, and was fixed in 5.4.1.
But in my case, it doesn't happen on the osx editor. It works just fine unless built to osx standalone.

I tested multiple osx machines and the same result occured. I couldn't tested on a windows machine.
So I submitted a bug report (case No. 949286), but hadn't been replyed by UnityQA on wether this was a bug / known issue or not.

Is there anyone experiencing similar issues? Or workaround or et cetra? Please help!

 

This issue no longer occurs on Unity 2017.1.1p3 . Thanks again to Aurimas from Unity QA for kind support!

 

How do I purchase the Android USB Serial plug-in?