
postage is no longer maintained and has been replaced by the identical pgmanage. See: https://github.com/workflowproducts/postage#postage-has-been-replaced-with-pgmanage The following error is raised when a user enables the deprecated `services.postage.enable` option: Failed assertions: - services.postage is deprecated in favor of pgmanage. They have the same options so just substitute postage for pgmanage.
To build the manual, you need Nix installed on your system (no need for NixOS). To install Nix, follow the instructions at https://nixos.org/nix/download.html When you have Nix on your system, in the root directory of the project (i.e., `nixpkgs`), run: nix-build nixos/release.nix -A manual.x86_64-linux When this command successfully finishes, it will tell you where the manual got generated.