Almost unmodified compared to the original in cargo-tree, should be fairly simple to move this and the dependency graph structure out to a library. TODO: Move this to a module to begin with.

find_unsafe

get_cfgs

TODO: Write proper documentation for this. This function seems to be looking up the active flags for conditional compilation (cargo::util::Cfg instances).

is_file_with_ext

is_test_fn

is_test_mod

Will return true for #[cfg(test)] decodated modules.

meta_is_word_test

meta_list_is_cfg_test

parse_rustc_dep_info

Copy-pasted (almost) from the private module cargo::core::compiler::fingerprint.

print_dependency

print_dependency_kind

print_tree

registry