Instruments can't attach to running process on iPhone

Question

I created a build for ad-hoc distribution of our product and installed the same on my device. Now I want to run the time profiler on the running process but Instruments is unable to attach to it. This is the error that I get when I try to attach to a running process on the iPhone:

Target failed to run : Could not attach to process <app-name> (<pid>)

I also tried "Choose Target" > app-name but that too failed with the following error:

Target failed to run : Remote exception encountered : 'Failed to get task for pid <pid>'

Here are the details of my setup:

• OS X 10.7.2
• Xcode 4.2.1 (Build 4D502)
• Instruments 4.2 (4233)
• iPhone OS 5.0.1 (Build 9A405)

Answer 1

I had the same problem. I didn't solve it initially, but an easy workaround is to launch the app yourself and then attach to it from the "Attach to Process..." command in the Target menu in the Instruments window.

1. After some digging around it seems this is a common topic of discussion on the apple developer forums: Instruments does not work on Xcode 4 with device

It appears that different Apple products will change/update the MobileDevice framework. Some of these updates break the Instruments integration.

1. To fix this on my own machine, I installed the iTunes 10.5 beta v6. Fire up XCode, and I'm back in business Instrumenting on my device.

2. I would recommend this tutorial since it is one of the better ones for explaining how to use Instruments

It can be very confusing at first, but take the time to get to know it and it'll ease a lot of headaches later.

Hope atleast one of these approaches work for you.