Has anyone looked into what it would take to make Boot play well with Nix, in the "let Nix manage downloading and caching" sense of "play well"? Nixpkgs has a boot package, but it doesn't appear that it can be used in the sandboxed, network-free build environment where Nix derivations are built.

(oh -- sandboxed, network-free, and persistent-home-directory-free as well)

...generally, running a build in Nix means giving Nix a list of everything that needs to be retrieved from a network -- whether that's a git checkout, a HTTP download, the result of a different set of build operations on software previously so downloaded, or whatever else -- ahead of time, receiving a list of paths with locations at which those items can be found (typically hash-addressed locations in a read-only shared store); and performing one's build steps in an isolated environment where only those declared inputs are available. (Oh -- and in typical "pure" mode, network sources can only be used when checksums for the downloaded content are known ahead-of-time).