flake: Add typo checker pass to check phase

Signed-off-by: Christoph Heiss <christoph@c8h4.io>

flake.nix

@@ -31,6 +31,25 @@
         rustToolchain = pkgs.rust-bin.stable."1.71.0".default;
 
         craneLib = (crane.mkLib pkgs).overrideToolchain rustToolchain;
+
+        cargoTypos = args:
+          craneLib.mkCargoDerivation (args // {
+            cargoArtifacts = null;
+            cargoVendorDir = null;
+
+            buildPhaseCargoCommand = "typos";
+            pnameSuffix = "-typos";
+
+            nativeBuildInputs = (args.nativeBuildInputs or [ ])
+              ++ (with pkgs; [ typos ]);
+
+            preInstallPhases = [ "ensureTargetDir" ]
+              ++ (args.preInstallPhases or [ ]);
+            ensureTargetDir = ''
+              mkdir -p ''${CARGO_TARGET_DIR:-target}
+            '';
+          });
+
         shouldRunCoverage = system == "x86_64-linux"
           && ((builtins.getEnv "CI") != "");
 
@@ -48,6 +67,7 @@
           srht-buildtest-doc =
             craneLib.cargoDoc { inherit src cargoArtifacts; };
           srht-buildtest-fmt = craneLib.cargoFmt { inherit src; };
+          srht-buildtest-typos = cargoTypos { inherit src; };
         } // lib.optionalAttrs shouldRunCoverage {
           srht-buildtest-coverage =
             craneLib.cargoTarpaulin { inherit src cargoArtifacts; };