Instruments does not work on XCode 4 with device

Question

Until very recently, instruments worked fine. I don't know what I did to make it mad, but now it won't attach to any device that I try to Profile with; no device at all. I've tried an iPhone, iPad, and 2 iPod touches; no luck! I'm using XCode 4.

Here is the sequence of events:

1. With device attached, click Product->Profile.
2. App compiles onto device.
3. Instruments launches, but an error sound is heard
4. The record button is grayed out.
5. Choose Target doesn't allow me to attach or choose target (empty list).

Background points:

1. Profile is set to Debug build within the Scheme of the project. This is true for all static libs as well.
2. I AM able to run the Core Animation instrumentation on the device, but only when I launch I launch Instruments separately from Xcode. In this scenario, i can only attach to an existing executable; I can't use "Choose Target" (the list is empty).
3. I tried restoring one of the devices to factory settings...still didn't work.

4. Looking at the Console of the device, i see these messages:

   unknown lockdownd[17] <Error>: 001d5000 handle_connection: Could not receive USB message #16 from Instruments. Killing connection
   unknown com.apple.mobile.lockdown[17] <Notice>: Could not receive size of message
   

Any help would be most appreciated

Answer 1

There was a discussion on the apple developer forums about this issue:

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.

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.

Answer 2

May be worth a try - I had the same issue - I changed 'Targeted Device Family' from 'iphone/ipad' to 'iphone' in the build settings and this solved it for me.