How to Debug an iPhone App Crash, Part 1: EXC_BAD_ACCESS

1. Run Build and Analyze: This kind of Build is very good at finding retain/release bugs. Take a good look at everything it flags.
2. Even better, run scan-build. I did a test recently, and found that some common errors are off by default in Build and Analyze that can be turned on in scan-build.
3. Choose Run > Enable Guard Malloc in the menu, and then re-run your application. This finds a whole class of buffer overrun issues. If this detects it, you’ll see a better error in the console.
4. You can instruct the compiler to ignore release calls and then report if anyone is sending messages to objects that would have been deallocated. This results in much better errors in the Console if it detects them.
5. Valgrind is the gold standard for finding memory bugs on Linux, and here’s a way to get it working in the iPhone Simulator.



Thanks to http://www.loufranco.com/blog/files/debug-iphone-crash-EXC_BAD_ACCESS.html