(Replying to list as well this time) > > Is there a way to force use of the Xcode SDK? > > use_xcode yes
Sorry, I should have mentioned that I tried that, but the result was that it still used the CLI SDK: SDKROOT='/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk' I am on macOS 10.15.7 19H15 Xcode 12.2 12B45b % ls -al /Library/Developer/CommandLineTools/SDKs total 0 drwxr-xr-x 5 root wheel 160 Nov 20 10:32 . drwxr-xr-x 5 root wheel 160 Nov 20 10:30 .. lrwxr-xr-x 1 root wheel 14 Nov 20 10:32 MacOSX.sdk -> MacOSX11.0.sdk drwxr-xr-x 8 root wheel 256 Jul 10 01:33 MacOSX10.15.sdk drwxr-xr-x 7 root wheel 224 Oct 20 05:39 MacOSX11.0.sdk -Aaron