To explicitly ensure, that CMake will use the GNU compiler use:
```{bash, engine='sh'}
...
...
@@ -14,6 +21,13 @@ export CXX=g++
export CC=gcc
```
Lookup the [compiler-flag](https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html) for your hardware. Change the `-march` flag in your `CMakeLists.txt` depending on the hardware.