Update CircleCI configuration to the new packaging

.circleci/config.yml

@@ -39,10 +39,10 @@ workflows:
       - "centos-8":
           {}
 
-      - "nixos-19-09":
+      - "nixos-21-05":
           {}
 
-      - "nixos-21-05":
+      - "nixos-21-11":
           {}
 
       # Test against PyPy 2.7
@@ -441,15 +441,16 @@ jobs:
         image: "tahoelafsci/fedora:29-py"
         user: "nobody"
 
-  nixos-19-09: &NIXOS
+  nixos-21.05: &NIXOS
     docker:
       # Run in a highly Nix-capable environment.
       - <<: *DOCKERHUB_AUTH
         image: "nixorg/nix:circleci"
 
     environment:
-      NIX_PATH: "nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-19.09-small.tar.gz"
-      SOURCE: "nix/"
+      # Reference the name of a niv-managed nixpkgs source (see `niv show` and
+      # nix/sources.json)
+      NIXPKGS: "nixpkgs-21.05"
 
     steps:
       - "checkout"
@@ -466,17 +467,13 @@ jobs:
             # build a couple simple little dependencies that don't take
             # advantage of multiple cores and we get a little speedup by doing
             # them in parallel.
-            nix-build --cores 3 --max-jobs 2 "$SOURCE"
+            nix-build --cores 3 --max-jobs 2 --argstr pkgsVersion "$NIXPKGS"
 
-  nixos-21-05:
+  nixos-21-11:
     <<: *NIXOS
 
     environment:
-      # Note this doesn't look more similar to the 19.09 NIX_PATH URL because
-      # there was some internal shuffling by the NixOS project about how they
-      # publish stable revisions.
-      NIX_PATH: "nixpkgs=https://github.com/NixOS/nixpkgs/archive/d32b07e6df276d78e3640eb43882b80c9b2b3459.tar.gz"
-      SOURCE: "nix/py3.nix"
+      NIXPKGS: "nixpkgs-21.11"
 
   typechecks:
     docker:

nix/sources.json

@@ -23,23 +23,23 @@
         "url": "https://github.com/nmattia/niv/archive/5830a4dd348d77e39a0f3c4c762ff2663b602d4c.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
-    "nixpkgs": {
-        "branch": "release-20.03",
+    "nixpkgs-21.05": {
+        "branch": "nixos-21.05",
         "description": "Nix Packages collection",
         "homepage": "",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "eb73405ecceb1dc505b7cbbd234f8f94165e2696",
-        "sha256": "06k21wbyhhvq2f1xczszh3c2934p0m02by3l2ixvd6nkwrqklax7",
+        "rev": "0fd9ee1aa36ce865ad273f4f07fdc093adeb5c00",
+        "sha256": "1mr2qgv5r2nmf6s3gqpcjj76zpsca6r61grzmqngwm0xlh958smx",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/eb73405ecceb1dc505b7cbbd234f8f94165e2696.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/0fd9ee1aa36ce865ad273f4f07fdc093adeb5c00.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs-21.11": {
         "branch": "nixos-21.11",
         "description": "Nix Packages collection",
         "homepage": "",
-        "owner": "nixos",
+        "owner": "NixOS",
         "repo": "nixpkgs",
         "rev": "6c4b9f1a2fd761e2d384ef86cff0d208ca27fdca",
         "sha256": "1yl5gj0mzczhl1j8sl8iqpwa1jzsgr12fdszw9rq13cdig2a2r5f",