Workflow for troubleshooting bugs on iOS device?

Hello,

I'm new to Unity and was wondering what the workflow is for fixing bugs on iPhone.

My game has been working fine when I run it in Unity, and fine on iPhone so far. However today I made a build and put it on my phone and I saw a bug occurring. It happened twice and now I can't replicate it. So my question not about how to fix that specific bug, but instead I'd like to know how to go about problem solving somet$$anonymous$$ng like t$$anonymous$$s. What are the standards and practices for figuring out the source of a problem that only occurs on the device? Is there a log of some sort that I can look at in Xcode to get more information? If I'm trying to fix it, is there a way to test it on the device other than going through the whole process of exporting a build from unity, opening it in xcode, and building/running it from there? It seems like it would take 10 minutes each time I want to check to see if the bug is fixed, so is there another way that I'm not aware of? Thanks for your help.