nix: update for rust-1.74

Updates the niv sources to pin for rust-1.74.

Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett

.nix/sources.json

@@ -5,10 +5,10 @@
         "homepage": "https://github.com/nmattia/niv",
         "owner": "nmattia",
         "repo": "niv",
-        "rev": "0ebb80e003c26d5388a9b74645fbdcfca3bdd0ef",
+        "rev": "723f0eeb969a730db3c30f977c2b66b9dce9fe4a",
-        "sha256": "0wpnk1n4vjyqwjjrm6dvkyh7xr7983rszfhfcg31v106qhfnh41c",
+        "sha256": "0016l7230gd2kdh0g2w573r9a2krqb7x4ifcjhhsn4h1bwap7qr0",
         "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/0ebb80e003c26d5388a9b74645fbdcfca3bdd0ef.tar.gz",
+        "url": "https://github.com/nmattia/niv/archive/723f0eeb969a730db3c30f977c2b66b9dce9fe4a.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs": {
@@ -29,10 +29,10 @@
         "homepage": "",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "32b17eeafe550935bd5ca1afd1717dcefcb97653",
+        "rev": "e17bfe3baa0487f0671c9ed0e9057d10987ba7f7",
-        "sha256": "0378dq5h67r1rlhq1is9r4cvka70n9lqrk504qq0w5jvcmvbl3yz",
+        "sha256": "1kg6kfkc115gcip69vrxz74ryfmh44fdx2480l6qahkgl0d3pzxb",
         "type": "tarball",
-        "url": "https://github.com/oxalica/rust-overlay/archive/32b17eeafe550935bd5ca1afd1717dcefcb97653.tar.gz",
+        "url": "https://github.com/oxalica/rust-overlay/archive/e17bfe3baa0487f0671c9ed0e9057d10987ba7f7.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }

.nix/sources.nix

@@ -27,16 +27,17 @@ let
   fetch_git = name: spec:
     let
       ref =
-        if spec ? ref then spec.ref else
+        spec.ref or (
           if spec ? branch then "refs/heads/${spec.branch}" else
           if spec ? tag then "refs/tags/${spec.tag}" else
-              abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
+          abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!"
-      submodules = if spec ? submodules then spec.submodules else false;
+        );
+      submodules = spec.submodules or false;
       submoduleArg =
         let
           nixSupportsSubmodules = builtins.compareVersions builtins.nixVersion "2.4" >= 0;
           emptyArgWithWarning =
-            if submodules == true
+            if submodules
             then
               builtins.trace
                 (
@@ -44,8 +45,8 @@ let
                   + "but your nix's (${builtins.nixVersion}) builtins.fetchGit "
                   + "does not support them"
                 )
-                {}
+                { }
-            else {};
+            else { };
         in
         if nixSupportsSubmodules
         then { inherit submodules; }
@@ -89,7 +90,7 @@ let
     if builtins.hasAttr "nixpkgs" sources
     then sourcesNixpkgs
     else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
-        import <nixpkgs> {}
+      import <nixpkgs> { }
     else
       abort
         ''
@@ -115,7 +116,7 @@ let
   # the path directly as opposed to the fetched source.
   replace = name: drv:
     let
-      saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
+      saneName = stringAsChars (c: if (builtins.match "[a-zA-Z0-9]" c) == null then "_" else c) name;
       ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
     in
     if ersatz == "" then drv else
@@ -132,7 +133,7 @@ let
   );
 
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
-  range = first: last: if first > last then [] else builtins.genList (n: first + n) (last - first + 1);
+  range = first: last: if first > last then [ ] else builtins.genList (n: first + n) (last - first + 1);
 
   # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
   stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
@@ -143,7 +144,7 @@ let
   concatStrings = builtins.concatStringsSep "";
 
   # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
-  optionalAttrs = cond: as: if cond then as else {};
+  optionalAttrs = cond: as: if cond then as else { };
 
   # fetchTarball version that is compatible between all the versions of Nix
   builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
@@ -151,7 +152,7 @@ let
       inherit (builtins) lessThan nixVersion fetchTarball;
     in
     if lessThan nixVersion "1.12" then
-        fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
+      fetchTarball ({ inherit url; } // (optionalAttrs (name != null) { inherit name; }))
     else
       fetchTarball attrs;
 
@@ -161,25 +162,28 @@ let
       inherit (builtins) lessThan nixVersion fetchurl;
     in
     if lessThan nixVersion "1.12" then
-        fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
+      fetchurl ({ inherit url; } // (optionalAttrs (name != null) { inherit name; }))
     else
       fetchurl attrs;
 
   # Create the final "sources" from the config
   mkSources = config:
-    mapAttrs (
+    mapAttrs
+      (
         name: spec:
           if builtins.hasAttr "outPath" spec
-        then abort
+          then
+            abort
               "The values in sources.json should not have an 'outPath' attribute"
           else
             spec // { outPath = replace name (fetch config.pkgs name spec); }
-    ) config.sources;
+      )
+      config.sources;
 
   # The "config" used by the fetchers
   mkConfig =
     { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
-    , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
+    , sources ? if sourcesFile == null then { } else builtins.fromJSON (builtins.readFile sourcesFile)
     , system ? builtins.currentSystem
     , pkgs ? mkPkgs sources system
     }: rec {
@@ -191,4 +195,4 @@ let
     };
 
 in
-mkSources (mkConfig {}) // { __functor = _: settings: mkSources (mkConfig settings); }
+mkSources (mkConfig { }) // { __functor = _: settings: mkSources (mkConfig settings); }