error: failed to attach to process ID 0

Question

I have been reading the forums and so far none of the solutions suggested works for me. I\'m running Xcode 4.4.1 and testing in iPhone 5.1 simulator. The simulator won\'t op

Answer 1

Some times it happens because you have two projects with same name. Try this:

1. go to xCode preference choose location and click on DerivedData delete the DerivedData
2. Reset and force Quit Simulator
3. Force Quit The Xcode and restart

If it has not worked than restart your PC.

Answer 2

This happens when you switch between versions of xcode. Simple solution is to quit xcode and simulator. Relaunch xcode and at the same time clean the simulator befor running. This should solve the problem.

Answer 3

I guess there exists someone who is in case the matter happens only in a project, not in every project and failed to resolve the matter after doing a lot of solutions posted on this Question page, such as 'deleting the App directy under ~/Library/Application Support/iPhone Simulator/6.0/Applications and ~/Library/Developer/Xcode/DerivedData', 'Cleaning all the logs by doing Project -> Clean' and 'Cleaning all the log and contents in the iOS Simulator Menu' and anything else.

Yes, I also finally failed to resolve that.

For you, It might be a solution if you are in the problem I mentioned above: Create a new project with a similar name, and copy and paste all of your classes and resourse files existing in your previous project folder to the new one and link the references between your new project and the copied files in Xcode. Then, clean the build logs by pressing 'Shift + Command + K'.

In my case, this made me able to continue my work...

Answer 4

Reset Simulator and quit simulator then Rebuild-Run.Its works for me

Answer 5

I had the same problem and I found that you can't be using the root account on your Mac. If you are logged in as root you are not able to attach process to the Simulator. You have to be logged in as a different account.

Answer 6

Finally, I found out the problem was I had a folder called "resources" that I used to store all my images. When I changed the name of the folder to something less likely to be used by XCode somewhere else, I did the whole delete derived data/clean/restart XCode and it worked!