# DLib {#dlib}
[DLib](http://dlib.net/) is a modern, C++\-based toolkit which provides several machine learning algorithms.
## Compiling without AVX support {#compiling-without-avx-support}
Especially older CPUs don't support [AVX](https://en.wikipedia.org/wiki/Advanced_Vector_Extensions) (Advanced Vector Extensions) instructions that are used by DLib to optimize their algorithms.
On the affected hardware errors like `Illegal instruction` will occur. In those cases AVX support needs to be disabled:
```nix
self: super: { dlib = super.dlib.override { avxSupport = false; }; }
```
