Why can't MEX find a supported compiler in MATLAB R2015a after I upgraded to Xcode 7.3?

I'm having a very similar problem to this issue. I recently installed Xcode 7.3 and am running Matlab 2015a. When I try and use Mex I get this error:

>> mex -setup
Warning: Xcode is installed, but its license has not been accepted. Run Xcode and accept its
license agreement.

Error using mex
No supported compiler or SDK was found. For options, visit 
http://www.mathworks.com/support/compilers/R2015a/maci64.html.

Unfortunately the solution for the previous issue doesn't work. I tried clearing up the "license not accepted warning" by upgrading to Xcode 7.3, but it persisted. I'm not sure if it's connected to the "no supported compiler" error. How do I fix this?

Edit: Adding a bit of information in case it's helpful. Running 'which clang' or 'which gcc' in Matlab gives me the following:

>> which gcc
'gcc' not found.
>> which clang
'clang' not found.

However I get the following in Terminal:

$ xcodebuild -find clang
/Applications/Xcode-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
$ xcodebuild -find gcc
/Applications/Xcode-beta.app/Contents/Developer/usr/bin/gcc

Answer 1

[Anushalakshmi Manila]

I have the same problem too!

Answer 2

[Walter Roberson]

You need to start XCode and click to agree to its license. After that you will be able to run.

[Greg]

Xcode is running. No box popped up asking about the license, and I've searched in Xcode looking for how to to accept it. How do I agree to the license?

[Walter Roberson]

Did you install the Xcode Command Line tools? http://www.mathworks.com/help/supportpkg/rtlsdrradio/ug/common-problems-and-fixes.html#bunsvm7-85

XCode -> Preferences -> Downloads -> Install command line tools

[Greg]

Thank you very much for helping. There's no Downloads tab in Xcode 7.3. Following the instructions here http://stackoverflow.com/questions/15371925/how-to-check-if-command-line-tools-is-installed it looks like Command Line Tools was not installed. I installed it by typing 'xcode-select --install' in Terminal. After installation I rebooted and restarted Matlab. But the problem persists - I get the same error when I try to use mex in Matlab. Any idea of what I could try next? Thanks again.

Answer 3

[kmiller]

I am experiencing the exactly same problem. No solutions by the MATLAB developers two months later?

[Walter Roberson]

The MATLAB Developers do not generally look at the Answers forum. It is not an official support channel. You can open a support case.