update niv

nix/sources.json

@@ -1,26 +1,14 @@
 {
-    "niv": {
-        "branch": "master",
-        "description": "Easy dependency management for Nix projects",
-        "homepage": "https://github.com/nmattia/niv",
-        "owner": "nmattia",
-        "repo": "niv",
-        "rev": "abd0de3269fd712955d27b70e32921841c7b8bb7",
-        "sha256": "0b38n1ad00s1qqyw3ml3pypf8i1pw4aqw0bpa02qq9iv7sp3x0gz",
-        "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/abd0de3269fd712955d27b70e32921841c7b8bb7.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
     "nixpkgs": {
         "branch": "nixos-unstable",
         "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
         "homepage": "https://github.com/NixOS/nixpkgs",
         "owner": "NixOS",
         "repo": "nixpkgs-channels",
-        "rev": "4557b9f1f50aa813ae673fe6fcd30ca872968947",
-        "sha256": "0cam48cn042axcik9vqxsqjc2hwyb2grjbjxacsn4w0y1zk6k6l2",
+        "rev": "aa561c6fb4f48974639a9e2b76fdd3e15b2abfd4",
+        "sha256": "15p0lbf227l26mvvpqi62nry3h0b249hig9fgpnsl6a3rlp6bj2v",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs-channels/archive/4557b9f1f50aa813ae673fe6fcd30ca872968947.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs-channels/archive/aa561c6fb4f48974639a9e2b76fdd3e15b2abfd4.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }

shell.nix

@@ -15,6 +15,7 @@ in pkgs.mkShell {
 
   buildInputs = [
     pkgs.git-crypt
+    pkgs.niv
     pkgs.nixops
   ];
 }