Simulink crashes when libstdc++.so.6 is replaced

Hi,

I'm using Matlab 2017b for Linux, and since Im getting the `GLIBCXX_3.4.21' not found' error when I'm compiling my s-func which includes a mex file that was built with gcc 5.x, I tried to follow the following post https://se.mathworks.com/matlabcentral/answers/329796-issue-with-libstdc-so-6

As suggested in this post I have tried to replace the libstdc++.so.6 under matlab installation path with the /usr/lib/x86_64-linux-gnu/libstdc++.so.6, but when I do this my model crashes immediately when I try to compile it.

I have realized that it is also immediately crashing when I completely delete the ibstdc++.so.6 under matlab installation path, or just create symbolic link to the /usr/lib/x86_64-linux-gnu/libstdc++.so.6.

Are there additional changes required?

Answer 1

[Pruthvi Muppavarapu]

Hi Goksan,

The issue might be due to incompatibility between the libstc++ shipped by MATLAB and the libstdc++ shipped with the system. Try to update the Standard C++ library in your Linux distribution the below steps:

• Open terminal and run the command:

sudo apt –get install libstdc++ 

• Re-launch Matlab.
• If the issue persists, then run the follwing commands in the termina:

 sudo add -apt -repository ppa:ubuntu-toolchain-r/test 
 sudo apt -get update  
 sudo apt -get upgrade  
 sudo apt -get dist-upgrade 

Regards,

Pruthvi

[Goksan ISIL]

Thanks for the suggestion Pruthvi.

When I have investigated the core dump, I have actually realized that the reason for the crash was that Matlab was looking for the wrong version of the libprotobuf.so, compared to the libprotobuf that I've used to generate my mex function.

I've used legacy code tool to generate a mex function and specified protobuf 3.5 version installation for the dependency folder. But when Matlab calls this mex function, it somehow tries to use it's own libprotobuf.so (an older version). Renaming the libprotobuf.so under matlab install directory to .old seems to allow me to run the mex function, but I guess since some internal matlab tools is using this libprotobuf.so library, I see some errors in the Matlab terminal like "error in matlab.internal.webwindow"

Luckily, these errors dont interfere with the simulation

[Stefan]

Hi @Goksan ISIL could you let me know how you found out libprotobuf was causing the issue. Thanks