https://releases.nixos.org/nixpkgs/17.09-darwin/nixpkgs-darwin-17.09pre117554.24a7883c234 1541867473 https://channels.nixos.org/nixpkgs-17.09-darwin 1583923244 https://releases.nixos.org/nixpkgs/17.09-darwin/nixpkgs-darwin-17.09pre117554.24a7883c234 1583929532 https://channels.nixos.org/nixpkgs-17.09-darwin 1584180642 1586372448 https://channels.nixos.org/nixpkgs-17.09-darwin 1586372742