mex returns errors, SDK and clang

Mac OS X 10.12.2, MATLAB 2016b, XCode 8.2.1, all installed today. I am attempting to mex a .c file.

*In Terminal, 
*xcodebuild: error: SDK "macosx10.8" cannot be located.
*xcrun: error: unable to find utility "clang", not a developer tool or in PATH
*In MATLAB,
*mex /Users/BullMini2/Desktop/'Alam Re-Re-Review'/F16Sim/nlplant.c
*Error using mex
*No supported compiler or SDK was found. For options, visit 
*http://www.mathworks.com/support/compilers/R2015b/maci64.html.
*'locate clang' in Terminal yields /usr/bin/clang
/usr/bin/clang++

MATLAB is installed at /Applications

Where did I go wrong?

Answer 1

[Bull Durham]

Disregard this question. Even though I upgraded to 2016b, 2015b was still present in /Applications and it was that version that was launched. Now launching 2016b with only warnings, but MEX completed

Answer 2

[Walter Roberson]

XCode 8 is not supported on R2016b:

http://www.mathworks.com/matlabcentral/answers/303782-is-xcode-8-compatible-with-matlab

But you can probably configure it using the same kind of operations as at http://www.mathworks.com/matlabcentral/answers/246507-why-can-t-mex-find-a-supported-compiler-in-matlab-r2015b-after-i-upgraded-to-xcode-7-0