The SDK in the Xcode.app and the SDK in the CLTs for MacOSX11.0.sdk are essentially identical (I just diff -ur'd them), so it doesn’t appear that the extra tools are in the SDK exactly.
So from that point of view, the 10.15 SDK in the CLTs might still be used if there is a good reason to do so, as Josh points out, if Xcode could still find the other tools it is looking for. The missing cdtool is here: % locate cdtool /Applications/Xcode.app/Contents/Developer/Library/Xcode/Agents/cdtool /Applications/Xcode.app/Contents/Developer/Platforms/AppleTVSimulator.platform/Developer/Library/Xcode/Agents/cdtool /Applications/Xcode.app/Contents/Developer/Platforms/WatchSimulator.platform/Developer/Library/Xcode/Agents/cdtool /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/Library/Xcode/Agents/cdtool I wonder how Xcode/xcodebuild goes about finding cdtools? It appears that xcodebuild is leveraging off the SDK location to find cdtools... K
