“Unable to locate compiler” mex error when using Visual C++ 2010 Express SP1 on 64-bit Windows

I had a working combination of Visual C++ 2010 Express and Microsoft Windows SDK 7.1. After installing Service Pack 1 for Visual Studio, I now get the following MEX error:

Error: Could not find the compiler "cl" on the DOS path. 
       Use mex -setup to configure your environment properly. 

     C:\Program Files\MATLAB\R2010B\BIN\MEX.PL: Error: Unable to locate compiler.

How can I get back to a working configuration?

Answer 1

[Ken Atwell]

This problem impacts MATLAB users with the following combination of software on 64-bit Windows (win64):

• Visual C++ 2010 Express
• Microsoft Windows SDK 7.1
• Visual Studio 2010 SP1

There is a bug in the installer for Visual Studio 2010 SP1. The installer will delete the 64-bit compiler previously installed by the SDK, or prevent the compiler from being later installed by the SDK.

This will prevent MEX and other products and features dependent on a compiler from functioning. "mex –setup" will continue to locate the Visual C++ compiler, but a "mex" call will later fail with a message like the following:

Error: Could not find the compiler "cl" on the DOS path. 
       Use mex -setup to configure your environment properly. 

     C:\Program Files\MATLAB\R2010B\BIN\MEX.PL: Error: Unable to locate compiler.

Microsoft has issued an update to address this issue. It is available for download at:

<http://www.microsoft.com/downloads/en/details.aspx?FamilyID=689655B4-C55D-4F9B-9665-2C547E637B70&displaylang=en>

After downloading and installing the update, MEX and other capabilities should work as anticipated.

[Faraz]

It still gives the problem

>> mex yprime.c

C:\PROGRA~1\MATLAB\R2010B\BIN\MEX.PL: Error: 'yprime.c' not found.

??? Error using ==> mex at 208

Unable to complete successfully.

What Next........?

[Ashish Uthama]

Faraz, as the error indicates, the file yprime.c was not found. Either provide the absolute path or change your working directory to where the file resides. Check your matlabroot/extern/examples/mex/ folder.

[Jan]

@Ken: Does this mean, that the SP1 of MSVC 2010 Express 2010 is compatible with Matlab 2011a? I'm not able to install the SDK SP1 currently, because the installer claims, that there are missing prerequisites.

[Mark Mikofski]

1. Yes, MSVC100 is still compatible with MATLAB 2011a/b x86 (for x64 you must have Windows SDK 7.1). See Supported and Compatible Compilers – Release 2011a.
2. Did you try clearing the "C++ compilers" check-box during install of Windows SDK 7.1? Then install the update.

From KB2519277:

If you try to install Windows SDK v7.1 after you upgrade to Visual Studio 2010 SP1, the Visual C++ compiler features might be blocked during the setup process. To resolve this issue, run the Windows SDK 7.1 Setup again, clear the Visual C++ Compilers check box, and then complete the setup. After Windows SDK v7.1 is installed, install the update that is described in the "Update information" section.

Also see Ken's posted solution.

[Jan]

@Mark: Does this "yes" concern my question? I asked for MSVC 2010 Express SP1, but the list of compatible compilers for R2011a/b mentions MSVC 2010 Express & Professional without service pack only. Even the technical support of TMW could not clear this question yet.

The thread is one year old. My problems are solved already.

Answer 2

[Bjoern]

Worked for me! Thx Ken

Answer 3

[K1]

Perfect! one way or another I hadn't found this answer... thank you!