Nix build c++ package on arm64 produces link errors

Hi everyone, absolute nix novice here trying to build a c++ project with nix.
I followed a tutorial to get this far.

The project I’m trying to build uses catch2_3 as a dependency. When i issue nix build . it fails at the very end with

> ld: symbol(s) not found for architecture arm64
> collect2: error: ld returned 1 exit status

Here is the nix-build branch for the project i’m trying to build.

I might be doing something wrong but it does appear to be working on a linux x86_64 machine and only fails on the M1 mac for me.
Any pointers very welcome. I have not been able to find much useful info online but being a novice I may have been looking in the wrong places.