Local registries for managing package sets and dependencies

[bladyjoker]

purescriptFlake, rustFlake and typescriptFlake all use a naive approach to adding packages to build environments from Nix using extraSources or dependencies argument.

https://github.com/mlabs-haskell/lambda-buffers/pull/191/files#diff-feaf943d43c786bde76a0f543430ba2efe06537a1d26a7eb4ef1e24da7edbcadR89 we see how this inevitably breaks the abstraction and the library needs to 'know' in which context it would be used.

In essence, any library that uses extraSources cannot itself be used as a dependency added through extraSources.

TODO

• Creating and managing local Cargo registries with Nix
• Creating and managing local Spago registries with Nix
• Creating and managing local NPM registries with Nix

[bladyjoker]

@jaredponn actually, are you using NPM registries somehow?