flake.nix: set /home/h7x4/.local/share/cargo for all relevant derivations

flake.nix

@@ -28,9 +28,11 @@
       };
 
       rust-bin = rust-overlay.lib.mkRustBin { } pkgs.buildPackages;
-      toolchain = rust-bin.stable.latest.default.override {
+      toolchain = (rust-bin.stable.latest.default.override {
         extensions = [ "rust-src" "rust-analyzer" "rust-std" ];
-      };
+      }).overrideAttrs (old: {
+        env.CARGO_HOME = "/tmp/cargo-home";
+      });
     in f system pkgs toolchain);
   in {
     devShells = forAllSystems (system: pkgs: toolchain: {
@@ -74,6 +76,8 @@
         version = cargoToml.package.version;
         inherit src;
 
+        env.CARGO_HOME = "/tmp/cargo-home";
+
         strictDeps = true;
         doCheck = false;
 
@@ -91,6 +95,8 @@
         strictDeps = true;
         doCheck = false;
 
+        env.CARGO_HOME = "/tmp/cargo-home";
+
         postPatch = ''
           '${lib.getExe pkgs.yq-go}' '.lib.crate-type = [ "staticlib" ]' --inplace Cargo.toml
         '';
@@ -117,6 +123,8 @@
         inherit src;
         strictDeps = true;
 
+        env.CARGO_HOME = "/tmp/cargo-home";
+
         buildInputs = with pkgs; [
           sqlite
         ];