I'm trying to install Xcode on High Sierra 10.13.6 and I'm having problems doing so. I'm getting error that I need to upgrade to 10.14 or higher but I don't want to upgrage my Mac OS. Is there and older version of Xcode that can be installed on my version of Mac (10.13.6)?
The current release of xcode is 11.5.1 (i think). Xcode 11.0 - 11.3 requires Mojave, Xcode 11.4.1 and above requires Catalina, so you would need to either update your OS or download Xcode 10 (probably Xcode 10.1).
I support bumping this to 10.0.0 as part of the bumps we are doing in LLVM 16.x anyway, but I am not an apple clang / xcode expert. So feel free to push back on that if you think we need more time to integrate this upgrade.
Ensure you have Xcode 9.0 or greater installed and selected (e.g. sudo xcode-select -s /Applications/Xcode.app/Contents/Developer), and that you have the command line tools installed (xcode-select --install). You also have to agree to the license by running sudo xcodebuild -license.