There are a number of "Valhalla unsupported" targets and tools contained within GitHub build and test actions, which fail:

E.g https://github.com/MrSimms/valhalla/actions/runs/319639572

* Linux x64 zero (unsupported target)
* Linux x64 minimal (unsupported target)
* Windows x64 release (compiler issue)
* Windows x65 debug (compiler issue)

These need to be either fixed or removed as build/test targets