Introduce nix into the project

.gitignore

@@ -1,2 +1,5 @@
 /target
 **/*.rs.bk
+
+/result
+/result-lib

flake.lock

@@ -0,0 +1,41 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1629481132,
+        "narHash": "sha256-JHgasjPR0/J1J3DRm4KxM4zTyAj4IOJY8vIl75v/kPI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "997f7efcb746a9c140ce1f13c72263189225f482",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1630832195,
+        "narHash": "sha256-9f1fN2joAFOkQ9KKNNNRaCjtRGXtmaJz2EWl5D+ztKM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "33e17471c8f04c8f7aae64b6938aa72dad2abaeb",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,27 @@
+{
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+  flake-utils.lib.eachSystem ["x86_64-linux"] (system:
+  let
+    pkgs = nixpkgs.legacyPackages.${system};
+    garbageProj = import ./Cargo.nix { inherit pkgs; };
+    garbage; = pkgs.lib.recursiveUpdate garbageProj.rootCrate.build {
+      meta = {
+        description = "CLI tool to interact with the FreeDesktop trash API.";
+        mainProgram = "garbage";
+      };
+    };
+    flakePkgs = {
+      inherit garbage;
+    };
+  in
+  rec {
+    packages = flake-utils.lib.flattenTree flakePkgs;
+    defaultPackage = flakePkgs.garbage;
+  });
+}
+
+# vim: set ts=2 sw=2 :

src/errors.rs

@@ -10,6 +10,9 @@ pub enum Error {
     #[error("IO error: {0}")]
     Io(#[from] std::io::Error),
 
+    #[error("Could not open file {0:?}: {1}")]
+    OpenFile(PathBuf, std::io::Error),
+
     #[error("Walkdir error: {0}")]
     WalkDir(#[from] walkdir::Error),