foo.nix

# something along these lines.  we add preConfigure so that python
# doesn't choke with some error about "not a valid wheel file name"
# and we override postInstall not to create the docbook manual
# because it failed and it was easier to do that than fix it

nixopsMaster = lib.overrideDerivation pkgs.nixops (a: rec {
      version = "1.6pre1_1675d7a";
      name = "nixops-${version}";
      # as of this date, no released version of nixops supports
      # writing /etc/hosts with the libvirtd backend
      src = fetchFromGitHub {
        owner = "NixOS";
        repo = "nixops";
        rev =  "1675d7a";
        sha256 = "1fly6ry7ksj7v5rl27jg5mnxdbjwn40kk47gplyvslpvijk65m4q";
      };
      preConfigure = ''
          for i in scripts/nixops setup.py doc/manual/manual.xml; do 
            substituteInPlace $i --subst-var-by version ${version}
          done
      '';
      postInstall = ''
          mkdir -p $out/share/nix/nixops
          cp -av "nix/"* $out/share/nix/nixops

          wrapProgram $out/bin/nixops --prefix PATH : "${openssh}/bin"
      '';

    });