How to set path to newly built GCC

I just built and installed gcc6.3.0 for MATLAB, but I can't set the path to it. I tried

export PATH=/home/mo/GCC-6.3.0:$PATH

but this still gives the path to default gcc9.3.0. Ubuntu20.04.

2 Answers

You would have to update the gcc configuration to make that your default compiler.

Add the compiler to the list of available compilers.

sudo update-alternatives --install /usr/bin/gcc gcc /path/to/installation/bin/gcc-6.3 6

Activate the compiler. This will prompt you to select a compiler.

sudo update-alternatives --config gcc

Verify whether the changes have taken effect with gcc --version

For security reasons, it is not recommended to add directories especially to the beginning of the path, as explained in this answer.

An easy way for me was to export gcc's path in terminal as:

export PATH=/home/mo/GCC-6.3.0/bin:$PATH

and then open MATLAB from this terminal window as:

cd /usr/local/MATLAB/R2019a/bin
./matlab

check gcc path in MATLAB:

!which gcc