# Debugging on OSX

**TODO: Figure out how to set breakpoints in Xcode**
**TODO: Figure out why Xcode detaches from the process after you take a Metal snapshot, leavin the window there forever**

## Basics

1. Open XCode
2. Create a new Project using the External Build Tool configuration
3. Set the Build Tool for the target to either:
  - `/usr/bin/true` - this is essentially a no-op if you want to be building elsewhere
  - `../bin/build.sh` (or similar) - the path to your build script. IMPORTANT: it seems Xcode doesn't resolve absolute paths, just paths relative to the project location.
4. With the project open go to `Product > Scheme > Edit Scheme > Run > Info > Executable` and select the executable you want to run. 
5. Cmd+R to Run.

Debugging this way, you can have Xcode run an executable in a .app or just from any directory. There do seem to be differences in the ways some graphics systems are initialized - I get different window scaling in each case.

## Graphics

### OpenGL
_I didn't have any luck with any of Xcode's graphics debugging utilities while developing for OpenGL._

### Metal
If you want to use XCode's Metal Graphics Debugging utilities, follow these steps:

1. `Product > Scheme > Edit Scheme > Diagnostics`
2. Turn on/off any options in the Metal section at the bottom.

*Note: Some of these will crash your app if you fail their checks.*

## Errors

**The specified architecture 'arm64-*-*' is not compatible with 'x86_64-apple-macosx10.13.0' in '/Users/ps/work/minos/p_scratch/package/scratch.app/Contents/MacOS/scratch'**
_This will happen if you are trying to debug an x86/x86_64 executable on an arm machine._

1. Go to Product > Destination > Destination Architectures > Show Both
2. Select Intel (Rosetta)

## Sources:
- [Basics](https://developer.apple.com/forums/thread/65025)
- [Video](https://www.youtube.com/watch?v=QVcjh6Kvnyw)