feat: update build script and docs to reference feature flags

README.md

@@ -25,13 +25,18 @@ compile with the latest stable Rust, I haven't tested older versions.
 In addition, you'll need development libraries for the following, which can
 probably be installed via your system package manager:
 
+- clang
 - glib
-- gdk-pixbuf
+- gdk-pixbuf (optional, provides support for non-PNG image formats)
 - pam
 - cairo
-- pango
+- pango (optional, provides support for system font loading)
 - xkbcommon
 
+gdk-pixbuf and pango are both optional, and are enabled with the features
+`gdk-pixbuf` and `pango` respectively. These features are enabled by default,
+you will need to disable them if you do not plan on using these libraries.
+
 With all of that, you should just be able to clone this repository, and run:
 
 ```sh

build.rs

@@ -21,6 +21,19 @@ fn main() {
         long_version.push(')');
     }
 
+    let mut features = Vec::new();
+    if cfg!(feature = "gdk-pixbuf") {
+        features.push("gdk-pixbuf");
+    }
+    if cfg!(feature = "pango") {
+        features.push("pango");
+    }
+    if !features.is_empty() {
+        long_version.push_str(" (");
+        long_version.push_str(features.join(" ").trim());
+        long_version.push(')');
+    }
+
     println!("cargo:rustc-env=NLOCK_VERSION={version}");
     println!("cargo:rustc-env=NLOCK_LONG_VERSION={long_version}");
 

nix/default.nix

@@ -12,6 +12,8 @@
   pkg-config,
   version ? "git",
   shortRev ? "unknown",
+  gdkPixbufSupport ? true,
+  pangoSupport ? true,
 }:
 
 rustPlatform.buildRustPackage {
@@ -24,6 +26,10 @@ rustPlatform.buildRustPackage {
     lockFile = ../Cargo.lock;
   };
 
+  buildNoDefaultFeatures = true;
+  buildFeatures =
+    [ ] ++ (lib.optional gdkPixbufSupport "gdk-pixbuf") ++ (lib.optional pangoSupport "pango");
+
   nativeBuildInputs = [
     installShellFiles
     clang
@@ -32,12 +38,12 @@ rustPlatform.buildRustPackage {
 
   buildInputs = [
     cairo
-    gdk-pixbuf
     glib
     libxkbcommon
     pam
-    pango
-  ];
+  ]
+  ++ (lib.optional gdkPixbufSupport gdk-pixbuf)
+  ++ (lib.optional pangoSupport pango);
 
   postInstall = ''
     installShellCompletion --cmd nlock \