NixOS/nixpkgs — pull request #3856 by nbp (2014-08-29 12:54:35+00:00)
Title: Annotate option-set options with the file in which they are declared.

This modification improves NixOS manual by listing in which file, each
submodule option is declared. This solve the issue that files are not
reported when looking at options such as fileSystems..neededForBoot