OSX - Failed to Launch … failed to get task for process

Question

I'm getting the following error:

error: failed to launch '/Users/alex/Library/Developer/Xcode/DerivedData/HeadCount-djmphvycpqkpfcdcdkaiokdhadhw/Build/Products/Debug/HeadCount.app/Contents/MacOS/HeadCount' -- failed to get the task for process 86433

There is no other entry in the debug log, the build log just says "Build Succeeded". And of course the process ID changes.

I've spent about an hour looking for an answer here and on Google, and this isn't an iOS application, it's a standard Mac app. I literally was working just fine, I made a small change to a method, and then tried to debug and am now receiving this error.

• This isn't a code signing error, as I've not been code signing the app and the "Code sign" checkbox is not checked, these settings haven't changed since I built it the first time.
• This isn't a provision/ad-hoc distribution error- I'm not distributing it to a phone.
• The scheme is set to Debug (I've also tried it set to Release, same result).
• If I manually browse to the app bundle and run it, I am able to run it properly.
• If I delete my DerivedData folder, the same error occurs.
• I do not have an entitlements.plist (my app used to have one, but I deleted it several days ago and disabled it in the build settings, it was working after I did that).
• My build target is OSX 10.8 and my environment is 10.8.
• My app is not running already- I double checked the Force Quit UI to make sure.

I've tried everything I can see in all the other topics that are similar to this, and I'm stumped. Any ideas?

Answer 1

From comments: Rebooting is the "sledgehammer" approach to fixing confused software. :-)

(I'd assume that something in the communication mechanism between Xcode and the app got messed up. With any luck, we'll never need to know the exact reason.)