@David-Healey I've fixed it - just incase anyone ever sees similar weirdness in future -
Open Terminal and:
xcode-select -p
That should return similar to:
/Applications/Xcode.app/Contents/Developer
If not, sort it with this:
sudo xcode-select --switch /Applications/Xcode.app
sudo xcodebuild -runFirstLaunch
Then reset dev tools:
sudo xcode-select --reset
sudo xcodebuild -license accept
Delete derived data and module cache:
rm -rf ~/Library/Developer/Xcode/DerivedData
rm -rf ~/Library/Developer/Xcode/ModuleCache.noindex
Double check clang if you've got clang errors:
clang --version
xcrun clang --version
If either of those hang, reinstall clang.
Reinstall commandlinetools:
sudo rm -rf /Library/Developer/CommandLineTools
xcode-select --install
Delete Xcode caches (bit severe but I think this is what sorted mine out):
rm -rf ~/Library/Caches/com.apple.dt.Xcode
rm -rf ~/Library/Preferences/com.apple.dt.Xcode.plist
Then reboot, open HISE and try your compile again - mine went straight through, no errors!