feat: add option to only extract runtime dependencies

Where runtime dependencies are defined as those in `buildInputs` and `propagatedBuildInputs`

src/lib.rs

@@ -49,6 +49,7 @@ pub struct ProcessingArgs<'a> {
     pub attribute_path: String,
     pub offline: bool,
     pub include_nar_info: bool,
+    pub runtime_only: bool,
     pub binary_caches: &'a Vec<String>,
     pub lib: &'a nix::lib::Lib,
     pub tx: mpsc::Sender<DerivationDescription>,
@@ -62,6 +63,7 @@ fn process(args: ProcessingArgs) -> Result<()> {
         args.system,
         &args.attribute_path,
         &args.offline,
+        &args.runtime_only,
         &args.include_nar_info,
         args.binary_caches,
         args.lib,
@@ -116,6 +118,7 @@ pub fn nixtract(
     attribute_path: Option<impl Into<String>>,
     offline: bool,
     include_nar_info: bool,
+    runtime_only: bool,
     binary_caches: Option<Vec<String>>,
 ) -> Result<impl Iterator<Item = DerivationDescription>> {
     // Convert the arguments to the expected types
@@ -165,6 +168,7 @@ pub fn nixtract(
                 system: &system,
                 attribute_path: found_drv.attribute_path,
                 offline,
+                runtime_only,
                 include_nar_info,
                 binary_caches: &binary_caches,
                 lib: &lib,

src/main.rs

@@ -77,6 +77,10 @@ struct Args {
     #[arg(long, default_value_t = false)]
     output_schema: bool,
 
+    /// Ouput only runtime dependencies
+    #[arg(long, short, default_value_t = false)]
+    runtime_only: bool,
+
     /// Write the output to a file instead of stdout or explicitly use `-` for stdout
     #[arg()]
     output_path: Option<String>,
@@ -116,6 +120,7 @@ fn main_with_args(opts: Args) -> Result<(), Box<dyn Error>> {
         opts.attribute_path,
         opts.offline,
         opts.include_nar_info,
+        opts.runtime_only,
         opts.binary_caches,
     )?;
 
@@ -175,6 +180,7 @@ mod tests {
                     // Write output to /dev/null to avoid cluttering the test output
                     output_path: Some("/dev/null".to_string()),
                     include_nar_info: false,
+                    runtime_only: false,
                     binary_caches: None,
                 };
 

src/nix/describe_derivation.nix

@@ -4,6 +4,7 @@
 #     TARGET_FLAKE_REF: flake reference to evaluate
 #     TARGET_SYSTEM: system to evaluate
 #     TARGET_ATTRIBUTE_PATH: attribute path to the derivation to evaluate
+#     RUNTIME_ONLY: 1 if you only want to include "buildInputs" (only runtime dependencies), 0 if you want all dependencies
 #
 # Example:
 # TARGET_FLAKE_REF="nixpkgs" TARGET_SYSTEM="x86_64-linux" TARGET_ATTRIBUTE_PATH="python3" nix eval --json --file describe-derivation.nix
@@ -16,6 +17,8 @@ let
   targetFlakeRef = builtins.getEnv "TARGET_FLAKE_REF";
   targetAttributePath = builtins.getEnv "TARGET_ATTRIBUTE_PATH";
   targetSystem = let env = builtins.getEnv "TARGET_SYSTEM"; in if env == "" then builtins.currentSystem else env;
+  # 0 is false, everything else is true
+  runtimeOnly = if builtins.getEnv "RUNTIME_ONLY" == "0" then false else true;
 
   # Get pkgs
   targetFlake = builtins.getFlake targetFlakeRef;
@@ -86,6 +89,9 @@ in
               (lib.enumerate (targetValue.${inputType} or [ ]))
           )
       )
-      [ "nativeBuildInputs" "buildInputs" "propagatedBuildInputs" ]
+      (
+        [ "buildInputs" "propagatedBuildInputs" ]
+        ++ nixpkgs.lib.optionals (!runtimeOnly) [ "nativeBuildInputs" ]
+      )
     );
 }

src/nix/describe_derivation.rs

@@ -71,6 +71,7 @@ pub fn describe_derivation(
     system: &Option<String>,
     attribute_path: &String,
     offline: &bool,
+    runtime_only: &bool,
     include_nar_info: &bool,
     binary_caches: &[String],
     lib: &Lib,
@@ -88,6 +89,10 @@ pub fn describe_derivation(
             ("NIXPKGS_ALLOW_UNFREE".to_owned(), "1".to_owned()),
             ("NIXPKGS_ALLOW_INSECURE".to_owned(), "1".to_owned()),
             ("NIXPKGS_ALLOW_BROKEN".to_owned(), "1".to_owned()),
+            (
+                "RUNTIME_ONLY".to_owned(),
+                if *runtime_only { "1" } else { "0" }.to_owned(),
+            ),
         ]);
         if let Some(system) = system {
             res.insert("TARGET_SYSTEM".to_owned(), system.to_owned());