rust-lang · Jules-Bertholet · Aug 14, 2026
diff --git a/bindgen-tests/tests/expectations/tests/typedef-void-newtype.rs b/bindgen-tests/tests/expectations/tests/typedef-void-newtype.rs
diff --git a/bindgen-tests/tests/headers/typedef-void-newtype.h b/bindgen-tests/tests/headers/typedef-void-newtype.h
@@ -0,0 +1,2 @@
+// bindgen-flags: --new-type-alias myvoid --with-derive-hash --with-derive-partialeq --with-derive-partialord --with-derive-eq --with-derive-ord --impl-debug --impl-partialeq
+typedef void myvoid;
diff --git a/bindgen/codegen/mod.rs b/bindgen/codegen/mod.rs
@@ -1112,7 +1112,11 @@ impl CodeGenerator for Type {
                             needs_debug_impl = ctx.options().derive_debug &&
                                 ctx.options().impl_debug &&
                                 !ctx.no_debug_by_name(item) &&
-                                !item.annotations().disallow_debug();
+                                !item.annotations().disallow_debug() &&
+                                !item.as_type().is_some_and(|ty| {
+                                    ty.safe_canonical_type(ctx)
+                                        .is_some_and(|ty| ty.is_void())
+                                });
                         }
                         let mut derives: Vec<_> = derivable_traits.into();
                         // The custom derives callback may return a list of derive attributes;
@@ -1126,7 +1130,9 @@ impl CodeGenerator for Type {
                             });
                         // In most cases this will be a no-op, since custom_derives will be empty.
                         append_custom_derives(&mut derives, &custom_derives);
-                        attributes.push(attributes::derives(&derives));
+                        if !derives.is_empty() {
+                            attributes.push(attributes::derives(&derives));
+                        }
 
                         let custom_attributes =
                             ctx.options().all_callbacks(|cb| {

diff --git a/bindgen/ir/analysis/derive.rs b/bindgen/ir/analysis/derive.rs
@@ -189,7 +189,6 @@ impl CannotDerive<'_> {
         match *ty.kind() {
             // Handle the simple cases. These can derive traits without further
             // information.
-            TypeKind::Void |
             TypeKind::NullPtr |
             TypeKind::Int(..) |
             TypeKind::Complex(..) |
@@ -213,6 +212,7 @@ impl CannotDerive<'_> {
             TypeKind::Function(ref sig) => {
                 self.derive_trait.can_derive_fnptr(sig)
             }
+            TypeKind::Void => CanDerive::No,
 
             // Complex cases need more information
             TypeKind::Array(t, len) => {
@@ -534,7 +534,6 @@ impl DeriveTrait {
             // === Default ===
             (
                 DeriveTrait::Default,
-                TypeKind::Void |
                 TypeKind::NullPtr |
                 TypeKind::Enum(..) |
                 TypeKind::Reference(..) |
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		// bindgen-flags: --new-type-alias myvoid --with-derive-hash --with-derive-partialeq --with-derive-partialord --with-derive-eq --with-derive-ord --impl-debug --impl-partialeq
		typedef void myvoid;