Fix --target-dir option

src/main.rs

@@ -48,8 +48,10 @@ fn try_main(coloring: &mut Option<Coloring>) -> Result<()> {
 fn exec_on_workspace(args: &Args, current_manifest: &Manifest, metadata: &Metadata) -> Result<()> {
     let mut line = ProcessBuilder::from_args(cargo_binary(), &args);
 
-    line.arg("--target-dir");
-    line.arg(args.target_dir.as_ref().unwrap_or(&metadata.target_directory));
+    if let Some(target_dir) = &args.target_dir {
+        line.arg("--target-dir");
+        line.arg(target_dir);
+    }
 
     if let Some(color) = args.color {
         line.arg("--color");

src/metadata.rs

@@ -22,8 +22,6 @@ use crate::Args;
 pub(crate) struct Metadata {
     /// A list of all crates referenced by this crate (and the crate itself)
     pub(crate) packages: Vec<Package>,
-    /// Build directory
-    pub(crate) target_directory: PathBuf,
     /// Workspace root
     pub(crate) workspace_root: PathBuf,
 }

src/process.rs

@@ -251,8 +251,8 @@ impl fmt::Display for ProcessBuilder {
         } else {
             let mut args = self.args.iter();
             while let Some(arg) = args.next() {
-                // Displaying `--target-dir` and `--manifest-path` is redundant.
-                if arg == "--target-dir" || arg == "--manifest-path" {
+                // Displaying `--manifest-path` is redundant.
+                if arg == "--manifest-path" {
                     let _ = args.next();
                     continue;
                 }