* This allows for fewer assumptions about the project structure
* The old behavior can easily be brought back by setting `cargoExtraArgs
= "--workspace";` in any derivation
* 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)
