mex错误：无法导出mexFunction：符号未定义

Question

当我运行MatConvNet的setup函数时，我收到以下错误：

>> setup
Warning: VL_NNCONV() does not seem to be compiled. Trying to compile it now. 
> In setup (line 14) 
Building with 'MinGW64 Compiler (C++)'.
Error using mex
Cannot export mexFunction: symbol not defined
collect2.exe: error: ld returned 1 exit status


Error in vl_compilenn>mex_compile (line 312)
  mex(mopts{:}) ;

Error in vl_compilenn (line 270)
obj_files = mex_compile(opts, cpp_src, bld_dir, mex_opts);

Error in setup (line 15)
  vl_compilenn('enableGpu', opts.useGpu, 'verbose', opts.verbose) ;

我没有mex编译器所以我安装了MinGW和MATLAB R2015b的指令。它看到了编译器，但它无法编译。我不知道如何解决这个问题。

感谢您的帮助！

修改

我在64位Windows 7上使用MATLAB R2015b，我安装的附加组件称为MATLAB Support for the MinGW-w64 C/C++ Compiler from TDM-GCC