Add flake.nix

Dependencies

• [2] ICYJNJWH Revert "Move build logic for the core hydra package into its own default.nix."
• [3] X7IAG7JT Simplify running nix-shell
• [4] WQ2VQ7H3 Use hydra-module.nix in the tests
• [*] CLXEECMF * Start putting build results in a database.
• [*] T4LLYESZ * Nix expression for building Hydra.

Change contents

• file addition: flake.lock (----------)
  [6.2]
  + {

  + "nonFlakeRequires": {},

  + "requires": {

  + "nixpkgs": {

  + "uri": "github:edolstra/nixpkgs/a4d896e89932e873c4117908d558db6210fa3b56"

  + }

  + },

  + "version": 1

  + }
• file addition: flake.nix (----------)
  [6.2]
  + {

  + name = "hydra";

  +

  + description = "A Nix-based continuous build system";

  +

  + epoch = 2019;

  +

  + requires = [ "nixpkgs" ];

  +

  + provides = deps: rec {

  +

  + hydraJobs = import ./release.nix {

  + hydraSrc = deps.self;

  + nixpkgs = deps.nixpkgs;

  + };

  +

  + packages.hydra = hydraJobs.build.x86_64-linux;

  +

  + defaultPackage = packages.hydra;

  + };

  + }
• replacement in release.nix at line 33
  [2.1]→[2.1:98](∅→∅)
  − version = builtins.readFile ./version + "." + toString hydraSrc.revCount + "." + hydraSrc.rev;
  [2.1]

  [3.413]
  + # FIXME: use commit date.

  + version = builtins.readFile ./version + "." + toString hydraSrc.revCount or 0 + "." + hydraSrc.shortRev or "0000000";