This is UnityDoorstop equivalent for Linux and macOS.
The library makes use of LD_PRELOAD and DYLD_INSERT_LIBRARIES injection.

Hooking is done with the help of plthook modified to work better with older Unity builds.

You need gcc and make to build this binary

To build both x64 and x86 binaries, run make. This can fail on newer macOSes that don't support building x86 binaries.

To build a specific version, use make build_x64 or make build_x86 depending on your architecture.

1. Put the built doorstop.so (or .dylib) and run.sh to the same directory as the game
2. Edit run.sh to configure Doorstop to work correctly
3. Run run.sh when you want to run your game modded
4. When you want to run vanilla game, run the game normally

You cannot directly run the Game.app, as it is just a folder. Instead, you must edit run.sh to execute Game.app/Contents/MacOS/Game (or other game executable depending on the Unity game).