* Seems like cachix is still pushing the results up to the cache, we
might as well get use of downloading the (empty) results rather than
having to pull down the intermediary binaries and running them each
time
* By default we pass everything through to the actual derivation itself,
but some internal parameters don't show up as environment variables
directly (or rather do not need to)
* In an effort to keep the build environment as lean as possible, we can
do some clean up (e.g. to avoid invalidating builds if some parameter
changes but is completely ignored/overridden elsewhere)
* Seems like whatever issue was preventing us from evaluating
derivations for other architectures (without actually building them)
has been resolved, and now we can nicely test everything with a single
invocation of `nix flake check`
