pin nixos-unstable, update flake.lock

`nixos-unstable` is the rolling release channel of NixOS. The default is
the master branch, which doesn't always have a populated binary cache
and so may result in compiling a bunch of stuff unnecessarily.

flake.lock

@@ -12,11 +12,11 @@
         "rust-overlay": "rust-overlay"
       },
       "locked": {
-        "lastModified": 1680584903,
-        "narHash": "sha256-uraq+D3jcLzw/UVk0xMHcnfILfIMa0DLrtAEq2nNlxU=",
+        "lastModified": 1686621798,
+        "narHash": "sha256-FUwWszmSiDzUdTk8f69xwMoYlhdPaLvDaIYOE/y6VXc=",
         "owner": "ipetkov",
         "repo": "crane",
-        "rev": "65d3f6a3970cd46bef5eedfd458300f72c56b3c5",
+        "rev": "75f7d715f8088f741be9981405f6444e2d49efdd",
         "type": "github"
       },
       "original": {
@@ -33,11 +33,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1680607374,
-        "narHash": "sha256-U5iiPqbAanr+sQCCZ7zxYhwCXdcDpish8Uy4ELZeXM0=",
+        "lastModified": 1687004852,
+        "narHash": "sha256-wRSUs+v8xtIJaFlWO5NLFQjkq5+eYhxHHXnZKsZ9DpQ=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "e70d498e97017daa59363eafa054619d4fa160c3",
+        "rev": "df0a6e4ec44b4a276acfa5a96d2a83cb2dfdc791",
         "type": "github"
       },
       "original": {
@@ -63,12 +63,15 @@
       }
     },
     "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
       "locked": {
-        "lastModified": 1678901627,
-        "narHash": "sha256-U02riOqrKKzwjsxc/400XnElV+UtPUQWpANPlyazjH0=",
+        "lastModified": 1685518550,
+        "narHash": "sha256-o2d0KcvaXzTrPRIo0kOLV0/QXHhDQ5DTi+OxcjO8xqY=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "93a2b84fc4b70d9e089d029deacc3583435c2ed6",
+        "rev": "a1720a10a6cfe8234c0e93907ffe81be440f4cef",
         "type": "github"
       },
       "original": {
@@ -79,15 +82,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1680652733,
-        "narHash": "sha256-FFG6Nai9M71C0Uc+D8TxyHoAjTplM0/9uWKsl7ALfUs=",
+        "lastModified": 1686960236,
+        "narHash": "sha256-AYCC9rXNLpUWzD9hm+askOfpliLEC9kwAo7ITJc4HIw=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "cc5bde408572508efd1273852862d418bb313443",
+        "rev": "04af42f3b31dba0ef742d254456dc4c14eedac86",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
+        "ref": "nixos-unstable",
         "repo": "nixpkgs",
         "type": "github"
       }
@@ -103,11 +107,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1680435407,
-        "narHash": "sha256-IPBtZCOh3BdrR+V77cL7r6WQnclWcZ/85BDYnmq/GnQ=",
+        "lastModified": 1686936697,
+        "narHash": "sha256-mCoPr1nNWKpsoGMBFaK/sswkLloRCZuoWi2a+OKs3vk=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "236576227a299fd19ba836b1834ab50c948af994",
+        "rev": "a5a71c75e62a0eaa1b42a376f7cf3d348cb5dec6",
         "type": "github"
       },
       "original": {
@@ -129,11 +133,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1680488274,
-        "narHash": "sha256-0vYMrZDdokVmPQQXtFpnqA2wEgCCUXf5a3dDuDVshn0=",
+        "lastModified": 1685759304,
+        "narHash": "sha256-I3YBH6MS3G5kGzNuc1G0f9uYfTcNY9NYoRc3QsykLk4=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "7ec2ff598a172c6e8584457167575b3a1a5d80d8",
+        "rev": "c535b4f3327910c96dcf21851bbdd074d0760290",
         "type": "github"
       },
       "original": {
@@ -141,6 +145,21 @@
         "repo": "rust-overlay",
         "type": "github"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -1,6 +1,6 @@
 {
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs";
+    nixpkgs.url = "github:NixOS/nixpkgs?ref=nixos-unstable";
     flake-utils.url = "github:numtide/flake-utils";
 
     fenix = {