"It appears the mexjulia MEX function is missing"

[jonniedie]

Following the steps in the README, I get this error in MATLAB:

>> jl.eval('2+2')
Error using jl.check_initialized (line 133)
It appears the mexjulia MEX function is missing. Consider building
"Mex.jl".\n

Error in jl.mexn (line 15)
            jl.check_initialized;

Error in jl.eval (line 38)
            [varargout{:}] = jl.mexn(nargin, 'Mex.jl_eval', varargin{:});

I tried this by building with Julia 1.5.3 and Julia 1.6.0 and got the same thing. Any thoughts?

[jebej]

The package doesn't work on 1.6 yet. For 1.5, I'll need more details:
What does mex -setup C++ say?

If it looks fine, you'll need to look at the build log file in the deps folder of the package.

[jonniedie]

>> mex -setup C++
MEX configured to use 'Microsoft Visual C++ 2017' for C++ language compilation.

And the build.log says

Error using mex
Unknown file extension ''.

C:\Users\jdiegelm\.julia\packages\Mex\ZlRZN\deps is not on the MATLAB path. Adding it and saving...

[jebej]

Looks like the mex call itself is failing. You should be able to open the jldict.mat file in the mexjulia folder. Could you then copy here the mex_cmd string? e.g. mine looks like:

mex LDFLAGS='-L"C:\Users\Jeremy\AppData\Local\Julia-1.5.4\bin" $LDFLAGS' -v -largeArrayDims -outdir "C:\Users\Jeremy\.julia\dev\Mex\deps\..\mexjulia" -O -I"C:\Users\Jeremy\AppData\Local\Julia-1.5.4\include\julia" -DJULIA_ENABLE_THREADING "C:\Users\Jeremy\.julia\dev\Mex\deps\mexjulia.cpp" C:\Users\Jeremy\AppData\Local\Julia-1.5.4\lib\libjulia.dll.a

You can also run the command directly in matlab and see what it outputs, in case the log file was missing some lines.

[jonniedie]

'mex LDFLAGS='-L"C:\Users\jdiegelm\AppData\Local\Programs\Julia 1.5.3\bin" $LDFLAGS' -v -largeArrayDims -outdir "C:\Users\jdiegelm\.julia\packages\Mex\ZlRZN\deps\..\mexjulia" -O -I"C:\Users\jdiegelm\AppData\Local\Programs\Julia 1.5.3\include\julia" -DJULIA_ENABLE_THREADING "C:\Users\jdiegelm\.julia\packages\Mex\ZlRZN\deps\mexjulia.cpp" C:\Users\jdiegelm\AppData\Local\Programs\Julia 1.5.3\bin\libjulia.dll.a'

Running it I get the error:

>> mex LDFLAGS='-L"C:\Users\jdiegelm\AppData\Local\Programs\Julia 1.5.3\bin" $LDFLAGS' -v -largeArrayDims -outdir "C:\Users\jdiegelm\.julia\packages\Mex\ZlRZN\deps\..\mexjulia" -O -I"C:\Users\jdiegelm\AppData\Local\Programs\Julia 1.5.3\include\julia" -DJULIA_ENABLE_THREADING "C:\Users\jdiegelm\.julia\packages\Mex\ZlRZN\deps\mexjulia.cpp" C:\Users\jdiegelm\AppData\Local\Programs\Julia 1.5.3\bin\libjulia.dll.a
Verbose mode is on.
Error using mex
Unknown file extension ''.

[jebej]

Ok, it looks fine. The only thing I can think of is that this is because you are using Visual C++, which I have never tried. I am using MinGW, installed via the MATLAB plugin interface.

[jonniedie]

Hm. I just installed MinGW and switched to that using mex -setup C++ and I'm getting the same errors.

[bardo84]

with Julia 1.6.2 and MinGW64 I'm getting
Error using mex g++: error: c:\users\xxx\appdata\local\programs\julia-1.6.2\bin\libjulia.dll.a: No such file or directory
whereas library path is pointing to bin
julia> dlpath("libjulia.dll") "c:\\users\\xxx\\appdata\\local\\programs\\julia-1.6.2\\bin\\libjulia.dll"

Related to the following?
https://github.com/JuliaLang/julia/issues/29812

[kongdd]

I am using Rtools MinGW64, and faced with the same question.
Any solution?