control the flake-compat version

default.nix

@@ -1,3 +1,6 @@
-(import (fetchTarball https://github.com/edolstra/flake-compat/archive/master.tar.gz) {
-  src = builtins.fetchGit ./.;
-}).defaultNix
+(import (let lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+in fetchTarball {
+  url =
+    "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+  sha256 = lock.nodes.flake-compat.locked.narHash;
+}) { src = ./.; }).defaultNix

flake.lock

@@ -1,5 +1,21 @@
 {
   "nodes": {
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1650374568,
+        "narHash": "sha256-Z+s0J8/r907g149rllvwhb4pKi8Wam5ij0st8PwAh+E=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "b4a34015c698c7793d592d66adbab377907a2be8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-utils": {
       "locked": {
         "lastModified": 1649676176,
@@ -65,6 +81,7 @@
     },
     "root": {
       "inputs": {
+        "flake-compat": "flake-compat",
         "flake-utils": "flake-utils",
         "naersk": "naersk",
         "nixpkgs": "nixpkgs_2"

flake.nix

@@ -3,6 +3,11 @@
     flake-utils.url = "github:numtide/flake-utils";
     naersk.url = "github:nix-community/naersk";
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+
+    flake-compat = {
+      url = "github:edolstra/flake-compat";
+      flake = false;
+    };
   };
 
   outputs = inputs:

shell.nix

@@ -1,3 +1,6 @@
-(import (fetchTarball https://github.com/edolstra/flake-compat/archive/master.tar.gz) {
-  src = builtins.fetchGit ./.;
-}).shellNix
+(import (let lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+in fetchTarball {
+  url =
+    "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+  sha256 = lock.nodes.flake-compat.locked.narHash;
+}) { src = ./.; }).shellNix