Are coroutines freezing my game?

I had a sequence scripted using Coroutines, which ran fine in the editor, but froze the build. Much googling and tweaking ensued. I decided to create a test case: a new project, added a GameObject with a TextMesh (for visual feedback), and a small script:

 void Start () {
         StartCoroutine (Test ());
     }
 
 IEnumerator Test () {
     TextMesh textMesh = gameObject.GetComponent<TextMesh> ();
     int i = 0;
     while (true) {
         textMesh.text = i.ToString();
         i++;
         yield return new WaitForSeconds (0.2f);
     }
 }

Straightforward test producing the expected results in the editor. However, at build time it would run as far as 9 and freeze. Force Quit was the only option. Development Build works as expected, perfectly. By the way, I'm on OS X 10.10.2, and updated Unity about an hour ago.

Can anyone shed some light on this?