I have videos and text instructions on my website https://anthonyirwin.com/adventure-game-studio-ags-macos-build/
The information and instructions above are absolutely fine, but here's also some of my own things I've noticed while working on the Steam/GOG Mac version of Zniw Adventure:
* if you wish to quickly (re)build your game *.app bundle, you can use the following script in the build directory with the CMakeList.txt file:
export BUILD=release
mkdir build_$BUILD
cd build_$BUILD
cmake -DCMAKE_BUILD_TYPE=$BUILD ..
make
* to have a unique icon of your app bundle, drop an
"ags.icns" Mac icon file into the "Resources" folder of your bundle. You can set both the
version, name, main executable, and the icon of your bundle by editing the keys of the Info.plist file inside your *.app:

* if you actually wish to sign, notarize and staple your game (in case Apple Thanos-snaps all unsigned apps from existence one day, just like they completely dropped 32-bit apps support), you will need a valid Apple dev ID:
codesign --force -v --sign "Your developer ID (your provider ID)" --options runtime --entitlements Entitlements.plist GameName.app
ditto -c -k --sequesterRsrc --keepParent *app yourGame.zip
xcrun altool --notarize-app --primary-bundle-id "your.bundle.id" --username your@email.com --password AppleOneTimePasswordHere --asc-provider YourProviderID --file yourGame.zip
After the notarization's done, you can verify your game, and staple it for offline use:
codesign --verify --verbose=4 YourGame.app
spctl --verbose=4 --assess --type execute YourGame.app
spctl -a -v YourGame.app
xcrun stapler staple -v YourGame.app
stapler validate YourGame.app
Additionally, if you do any changes to your game bundle (like a little patch, update, even a small change in the Resources directory), you
need to re-sign and re-notarize it again.
* if you wish to locally test your debug build with Steam/GOG dylibs, you need proper entitlements in your Entitlements.plist file (the one you use to sign the app), otherwise your game will crash and burn while trying to access Galaxy/Steam shared libs:
