Also update README example 2

README.md

@@ -175,12 +175,7 @@ Here's how we can set up our flake to achieve our goals:
         # Also run the crate tests under cargo-tarpaulin so that we can keep
         # track of code coverage
         myCrateCoverage = craneLib.cargoTarpaulin (commonArgs // {
-          # In this case we are choosing to only run our tarpaulin tests after
-          # we've checked everything with clippy first. If we do not want this
-          # we can uncomment the next line and delete the second one.
-
-          # inherit cargoArtifacts;
-          cargoArtifacts = myCrateClippy;
+          inherit cargoArtifacts;
         });
       in
       {
@@ -236,40 +231,56 @@ build.
         };
 
         craneLib = crane.lib.${system};
+        # Common derivation arguments used for all builds
+        commonArgs = {
           src = ./.;
 
+          buildInputs = with pkgs; [
+            # Add extra build inputs here, etc.
+            # openssl
+          ];
+
+          nativeBuildInputs = with pkgs; [
+            # Add extra native build inputs here, etc.
+            # pkg-config
+          ];
+        };
+
         # Build *just* the cargo dependencies, so we can reuse
         # all of that work (e.g. via cachix) when running in CI
-        cargoArtifacts = craneLib.buildDepsOnly {
-          inherit src;
-        };
+        cargoArtifacts = craneLib.buildDepsOnly (commonArgs // {
+          # Additional arguments specific to this derivation can be added here.
+          # Be warned that using `//` will not do a deep copy of nested
+          # structures
+          pname = "mycrate-deps";
+        });
 
         # First, run clippy (and deny all warnings) on the crate source.
-        my-crate-clippy = craneLib.cargoClippy {
-          inherit cargoArtifacts src;
+        myCrateClippy = craneLib.cargoClippy (commonArgs // {
+          # Again we apply some extra arguments only to this derivation
+          # and not every where else. In this case we add some clippy flags
+          inherit cargoArtifacts;
           cargoClippyExtraArgs = "-- --deny warnings";
-        };
+        });
 
         # Next, we want to run the tests and collect code-coverage, _but only if
         # the clippy checks pass_ so we do not waste any extra cycles.
-        my-crate-coverage = craneLib.cargoTarpaulin {
-          inherit src;
-          cargoArtifacts = my-crate-clippy;
-        };
+        myCrateCoverage = craneLib.cargoTarpaulin (commonArgs // {
+          cargoArtifacts = myCrateClippy;
+        });
 
         # Build the actual crate itself, _but only if the previous tests pass_.
-        my-crate = craneLib.buildPackage {
-          cargoArtifacts = my-crate-coverage;
-          inherit src;
-        };
+        myCrate = craneLib.buildPackage (commonArgs // {
+          cargoArtifacts = myCrateCoverage;
+        });
       in
       {
-        defaultPackage = my-crate;
+        defaultPackage = myCrate;
         checks = {
          inherit
            # Build the crate as part of `nix flake check` for convenience
-           my-crate
-           my-crate-coverage;
+           myCrate
+           myCrateCoverage;
         };
       });
 }