Why can't MEX find a supported compiler in MATLAB R2017a in macOS Sierra

I'm using the latest macOS (Sierra 10.12.5) and mex can not find the compiler, or SDK even if the latest Xcode (8.3.3) and Intel Paralell Studio are installed.

Answer 1

[Walter Roberson]

See https://www.mathworks.com/matlabcentral/answers/243868-mex-can-t-find-compiler-after-xcode-7-update-r2015b#comment_407066 for my files. I have tested them on Sierra with XCode 8.3 using R2017a.

[Peter Kerekes]

Thank you for your answer ! I have tried what was written in the link, but it still not works. Do you have any ideal what else can i do ?

[Walter Roberson]

Please show the output of

mex -v -setup

[Peter Kerekes]

This is the output:

[Walter Roberson]

Please copy and paste the entire text, so I can read the parts that got cut off.

Did you happen to install a pre-release or beta version of XCode? Those get put into a different location.

[Peter Kerekes]

>> mex -v -setup
Verbose mode is on.
... Looking for compiler 'Xcode with Clang' ...
... Looking for environment variable 'DEVELOPER_DIR' ...No.
... Executing command 'xcode-select -print-path' ...Yes ('/Library/Developer/CommandLineTools').
... Looking for folder '/Library/Developer/CommandLineTools' ...Yes.
... Executing command 'which xcrun' ...Yes ('/usr/bin/xcrun').
... Looking for folder '/usr/bin' ...Yes.
... Executing command 'defaults read com.apple.dt.Xcode IDEXcodeVersionForAgreedToGMLicense' ...No.
... Executing command 'defaults read /Library/Preferences/com.apple.dt.Xcode IDEXcodeVersionForAgreedToGMLicense' ...Yes ('8.3.3').
... Executing command '
agreed=8.3.3 
 if echo $agreed | grep -E '[\.\"]' >/dev/null; then 
 lhs=`expr "$agreed" : '\([0-9]*\)[\.].*'` 
  rhs=`expr "$agreed" : '[0-9]*[\.]\(.*\)$'` 
 if echo $rhs | grep -E '[\."]' >/dev/null; then 
 rhs=`expr "$rhs" : '\([0-9]*\)[\.].*'` 
 fi 
 if [ $lhs -gt 4 ] || ( [ $lhs -eq 4 ] && [ $rhs -ge 3 ] ); then 
 echo $agreed 
 else 
 exit 1
 fi 
 fi' ...Yes ('8.3.3').
... Executing command 'xcode-select -print-path' ...Yes ('/Library/Developer/CommandLineTools').
... Looking for folder '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk' ...No.
... Looking for folder '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk' ...No.
... Looking for folder '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk' ...No.
... Looking for folder '/Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk' ...No.
... Executing command 'find /Library/Developer/CommandLineTools -name MacOSX10.9.sdk' ...No.
... Executing command 'find $$ -name MacOSX10.10.sdk' ...No.
... Executing command 'find $$ -name MacOSX10.11.sdk' ...No.
... Executing command 'find $$ -name MacOSX10.12.sdk' ...No.
Did not find installed compiler 'Xcode with Clang'.
Error using mex
No supported compiler or SDK was found. For options, visit
http://www.mathworks.com/support/compilers/R2017a/.

>>

[Peter Kerekes]

I think I'm not using a pre-release or beta Xcode, I use the latest version of it (8.3.3)

[Walter Roberson]

Please show the output of

ls  /Library/Developer/CommandLineTools/Platforms/MacOSX.platform/Developer/SDKs
ls /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs

[Peter Kerekes]

The two outputs:

[Walter Roberson]

Okay, so your actual compiler is the same place mine is, but for some reason xcode-select -print-path is returning a different location where the compilers are not installed. I have only seen that happen before when a beta / pre-release XCode had been installed.

I will ensure that my Sierra virtual machine is up to date and then probe the operation of the xcode-select

[Walter Roberson]

I do not know why it is reporting that directory, but what you should do is go to the terminal and command

xcode-select --switch /Applications/Xcode.app

after that it should work.

[Peter Kerekes]

thank you very much, it's working now

[Natasha M Drissi]

I had the same problem and so I tried to see if I could solve it the same way but when I do I get this message instead

 error: --switch must be run as root (e.g. `sudo xcode-select --switch <xcode_folder_path>`).

[Walter Roberson]

Okay, so use sudo then...

sudo xcode-select --switch /Applications/Xcode.app

Answer 2

[Vahan Petrosyan]

Building with 'Xcode with Clang'.
/usr/bin/xcrun -sdk macosx/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk clang -c -DUSE_MEX_CMD   -DMATLAB_MEX_FILE -I"/usr/local/include"  -I"/Applications/MATLAB_R2017b.app/extern/include" -I"/Applications/MATLAB_R2017b.app/simulink/include" -fno-common -arch x86_64 -mmacosx-version-min=10.13 -fexceptions -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk -O2 -fwrapv -DNDEBUG "/Users/vahan/Desktop/research/Image Segmentation/algorithms/SEEDS LSC/timestwo.c" -o /var/folders/9t/cj2m3vms6l3_sdmj0nxqxch80000gn/T/mex_38352988742257_1467/timestwo.o
Error using mex
xcodebuild: error: SDK
"macosx/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.13.sdk" cannot be
located.
xcrun: error: unable to find utility "clang", not a developer tool or in PATH

• I am receiving the following error. It seems that after -sdk, my directory starts from maxosx. Can someone tell me what do to ?

[Walter Roberson]

Try (from Terminal)

sudo xcode-select --switch /Applications/Xcode.app

[Adawat Chanchua]

Thanks, you mad my day.