How to switch between multiple Command Line Tools

Question

Is it possible to install and switch between multiple version of Command Line Tools in Mac OS X? I was wondering if it's possible use xcode-select but the Command Line Tools installer doesn't have an option to choose the installation destination. I tried to create multiple installations by manually renaming Library/Developer/CommandLineTools and then passing it to xcode-select. The command succeeds but when I try to access gcc I get:

gcc: error: unable to find Xcode installation from active developer path "/Library/Developer/CommandLineTools_9.0.0", use xcode-select to change

It seems this is possible when installing the whole XCode but I have no need for XCode and prefer not to install it. All I need is the command line tools.

Answer 1

I tried to do the same and after some experiments found the next solution. Yes, it is possible but you need to copy/rename the whole /Library/Developer folder. For example:

1) first, I just show my macOS version:

$ sw_vers 
ProductName:    Mac OS X
ProductVersion: 10.13.6
BuildVersion:   17G65

2) download and install Command Line Tools for Xcode, e.g. 10b5 version

3) create folders to store different versions of tools:

$ mkdir ~/Project/tools
$ mkdir ~/Projects/tools/Developer10b5
$ mkdir ~/Projects/tools/Developer9.4.1

4) copy the whole Developer folder:

$ cp -R /Library/Developer/ ~/Project/tools/Developer10b5/

5) then, download and install Command Line Tools for Xcode, e.g. 9.4.1 version

6) copy the whole Developer folder:

$ cp -R /Library/Developer/ ~/Project/tools/Developer9.4.1/

7) switch to 9.4.1 version of tools and check the clang version:

$ sudo xcode-select -s ~/Project/tools/Developer9.4.1/
$ clang --version

Apple LLVM version 9.1.0 (clang-902.0.39.2)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir: /Users/<username>/Projects/tools/Developer9.4.1/CommandLineTools/usr/bin

8) switch to 10b5 version of tools and check the clang version:

$ clang --version
Apple LLVM version 10.0.0 (clang-1000.10.40.1)
Target: x86_64-apple-darwin17.7.0
Thread model: posix
InstalledDir: /Users/<username>/Projects/tools/Developer10b5/CommandLineTools/usr/bin