gcc 降级

运行ECO的demo 程序install.m 时遇到以下错误:

>> install
 
... Build routine for mtimesx
... Checking for PC
building linux version
Building with 'gcc'.
Warning: You are using gcc version '5.4.0'. The version of gcc is not supported. The version currently supported with MEX is
'4.9.x'. For a list of currently supported compilers see: http://www.mathworks.com/support/compilers/current_release. 
> In mtimesx_build (line 111)
  In install (line 10) 
/media/yuuzh/dataDisk2T/datasetTookit/vot/TrackerCode/ECO/external_libs/mtimesx/mtimesx.c: In function ‘mexFunction’:
/media/yuuzh/dataDisk2T/datasetTookit/vot/TrackerCode/ECO/external_libs/mtimesx/mtimesx.c:592:10: warning: assignment discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
      ans = mexGetVariablePtr("caller","OMP_SET_NUM_THREADS");
          ^

MEX completed successfully.
Warning: PDollars toolbox not found. Clone this submodule if you want to use HOG features. Skipping for now. 
> In install (line 22) 
Warning: Matconvnet not found. Clone this submodule if you want to use CNN features. Skipping for now. 
> In install (line 49) 

查找原因：

Since you have a higher version of gcc which is currently not supported in MATLAB R2017b, you will have to install GCC C/C++ 4.9 or higher versions till GCC 5.3 for it to be able to run the MEX. You can check the list of supported compatible compilers https://in.mathworks.com/support/compilers.html

那么降级就可以了：