# Fixing MATLAB on Fedora

The other week I had to set up a new installation of MATLAB r2016a on a (somewhat) fresh Fedora installation. After running the installer, I ran into a bunch of library errors when trying to run external C++ programs^{1} from MATLAB or when trying to plot something. When running an external C++ program, MATLAB would complain about missing versions of `CXXABI`

and `GLIBCXX`

in `libstdc++`

^{2}. When plotting something, MATLAB would complain about `libmwosgserver.so`

.

The first problem is caused by MATLAB trying to use its own, older version of `libstdc++`

. The second problem is caused by MATLAB trying to use the system’s version of `libmwosgserver`

. To fix the error when running C++ programs, I had to tell MATLAB to use the system’s version of `libstdc++`

. To fix the error when plotting, I had to tell MATLAB to use its own OpenGL libraries rather than the system’s.

The fixes are easy to make, you need to edit a couple of lines in a startup script. First of all, find out where the system’s version of `libstdc++`

is located (`$`

indicates text to enter in a shell):

```
$ find /usr -name 'libstdc++.so.6' -exec dirname '{}' \;
/usr/local/MATLAB/R2016a/sys/os/glnxa64
/usr/lib64
/usr/lib
```

The first line is MATLAB’s version of the library, the second the system’s 64-bit version of the library, the third the system’s 32-bit version. If you’re somehow still on a 32-bit system you’ll need to note down the path `/usr/lib`

. Otherwise, the path you need is `/usr/lib64`

. Now you need to edit MATLAB’s init script. The exact location will depend on where you installed MATLAB to. Assuming you installed MATLAB into the `/usr/local`

directory then you’ll need to edit `/usr/local/MATLAB/R2016a/bin/.matlab7rc.sh`

.

This script is essentially a massive switch statement that sets different environment variables depending on which operating system and architecture you’re on. Find the case statement corresponding to your architecture (`glnxa64`

for 64-bit Linux) which will look something like this:

```
case "$ARCH" in
glnx86|glnxa64)
```

For me that was around line 164 but it will probably depend on which version of MATLAB you’re running. Inside this case, find the line that says

```
LDPATH_PREFIX=""
```

and change it to

```
LDPATH_PREFIX="$MATLAB/sys/opengl/lib/$ARCH:/usr/lib64"
```

This pushes MATLAB’s OpenGL libraries and the system’s C++ libraries to the front of MATLAB’s load path, forcing it to use those versions of the libraries. Save the file, restart MATLAB and you should be good to go.