Matlab Coder: No rule to make target c_mexapi_version.o

Hey everybody! I'm trying to convert a time-costly loop I have into a MEX file that I can call from the rest of my MATLAB function, but I'm having trouble compiling it.

I get the following printouts when trying to compile it:

------------------------------------------------------------------------
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "run_trials_data.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "run_trials_initialize.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "run_trials_terminate.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "run_trials.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "normrnd.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "indexShapeCheck.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "interface/_coder_run_trials_info.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "interface/_coder_run_trials_api.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "interface/_coder_run_trials_mex.c"
gcc -c -fexceptions -fno-omit-frame-pointer -DTARGET_API_VERSION=700   -m64 -DMATLAB_MEX_FILE  -DMATLAB_MEX_FILE   -g    -I "D:\Program Files\MATLAB\R2017a/simulink/include" -I "D:\Program Files\MATLAB\R2017a/toolbox/shared/simtargets" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base\codegen\mex\run_trials" -I "D:\Users\Andrew\Google Drive\UCSB\Computational Cognitive Neuroscience Research\Development Code Base" -I ".\interface" -I "D:\Program Files\MATLAB\R2017a\extern\include" -I "." "run_trials_emxutil.c"
gmake: *** No rule to make target `c_mexapi_version.o', needed by `run_trials_mex.mexw64'.  Stop.

------------------------------------------------------------------------

I used the Matlab Coder application to automatically generate a build script, which invokes the following command that causes this error:

%%Invoke MATLAB Coder.
codegen -config cfg run_trials -args ARGS{1}

I'd appreciate pointers as to how to fix this make issue. Thanks!

[Ryan Livingston]

I would expect to see a line calling GCC on the file:

MATLABROOT\extern\version\c_mexapi_version.c

This sounds like either something may be missing from your installation or there may be an issue in the Makefile that Coder produced.

Two possible debugging steps:

1. What is the output of:

ls([matlabroot '/extern/version/'])

from inside your MATLAB installation? Mine shows:

>> ls([matlabroot '/extern/version/'])
c_mexapi_version.c  cpp_mexapi_version.cpp  fortran_mexapi_version.F

2. Can you ZIP or TAR your entire codegen directory and attach it here? That may give us a clue as to what happened.

Beyond that, I'd recommend getting in touch with technical support since we'll possibly need to check several things on your system to isolate the issue.

[Andrew Tran]

Hey Ryan, thanks for your response!

1. I get similar output running that command.

>> ls([matlabroot '/extern/version/'])
.                         ..                        c_mexapi_version.c        cpp_mexapi_version.cpp    fortran_mexapi_version.F

2. I have also attached a ZIP of my codegen directory (I assumed you meant the one generated by the script) as codegen.zip.

[Ryan Livingston]

OK that helps. If you look at the file run_trials_mex.mk you'll notice that c_mexapi_version.c is indeed in the source files SRC_FILES.

However, you'll notice that MATLAB_ROOT and START_DIR both have spaces in them:

D:\Program Files\MATLAB\R2017a

Coder typically uses the Windows short name (like C:\PROGRA~1\MATLAB\R2017a) to avoid issues with Makefiles and spaces in paths but such names can be disabled. My theory is that this is why the file from MATLABROOT isn't matching the targets further down in the file.

This answer:

https://www.mathworks.com/matlabcentral/answers/95399-why-is-the-build-process-failing-for-a-shipped-model-in-simulink-or-for-a-model-run-in-accelerator-m

describes the situation in great detail for Simulink and gives steps to enable short names if possible. It also gives workarounds if doing so isn't possible.

[Andrew Tran]

Hey Ryan, following the first suggestion on the solution list of manually creating a short name fixed my problem! It now compiles (and I believe runs properly). Thanks for your help!

[Walter Roberson]

Ryan: Andrew suggests moving your comment into an Answer so that Andrew can Accept it as the solution.

Answer 1

[Ryan Livingston]

Edit

A bug report:

https://www.mathworks.com/support/bugreports/1552846

has been published for this issue that includes a patch for MATLAB R2017a. It is recommended to install that patch to resolve this.

Original Answer with Manual Fix

If you look at the file run_trials_mex.mk you'll notice that c_mexapi_version.c is indeed in the source files SRC_FILES.

However, you'll notice that MATLAB_ROOT and START_DIR both have spaces in them:

D:\Program Files\MATLAB\R2017a

Coder typically uses the Windows short name (like C:\PROGRA~1\MATLAB\R2017a) to avoid issues with Makefiles and spaces in paths but such names can be disabled. My theory is that this is why the file from MATLABROOT isn't matching the targets further down in the file.

This answer:

https://www.mathworks.com/matlabcentral/answers/95399-why-is-the-build-process-failing-for-a-shipped-model-in-simulink-or-for-a-model-run-in-accelerator-m

describes the situation in great detail for Simulink and gives steps to enable short names if possible. It also gives workarounds if doing so isn't possible.