diff --git a/compiler/rustc_middle/src/ty/print/mod.rs b/compiler/rustc_middle/src/ty/print/mod.rs
index 107b44285ac0e..6835396b7a867 100644
--- a/compiler/rustc_middle/src/ty/print/mod.rs
+++ b/compiler/rustc_middle/src/ty/print/mod.rs
@@ -31,70 +31,70 @@ pub trait Printer<'tcx>: Sized {
     fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
 
     fn print_def_path(
-        self,
+        &mut self,
         def_id: DefId,
         args: &'tcx [GenericArg<'tcx>],
-    ) -> Result<Self, PrintError> {
+    ) -> Result<(), PrintError> {
         self.default_print_def_path(def_id, args)
     }
 
     fn print_impl_path(
-        self,
+        &mut self,
         impl_def_id: DefId,
         args: &'tcx [GenericArg<'tcx>],
         self_ty: Ty<'tcx>,
         trait_ref: Option<ty::TraitRef<'tcx>>,
-    ) -> Result<Self, PrintError> {
-        self.default_print_impl_path(impl_def_id, args, self_ty, trait_ref)
+    ) -> Result<(), PrintError> {
+        &mut self.default_print_impl_path(impl_def_id, args, self_ty, trait_ref)
     }
 
-    fn print_region(self, region: ty::Region<'tcx>) -> Result<Self, PrintError>;
+    fn print_region(&mut self, region: ty::Region<'tcx>) -> Result<(), PrintError>;
 
-    fn print_type(self, ty: Ty<'tcx>) -> Result<Self, PrintError>;
+    fn print_type(&mut self, ty: Ty<'tcx>) -> Result<(), PrintError>;
 
     fn print_dyn_existential(
-        self,
+        &mut self,
         predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
-    ) -> Result<Self, PrintError>;
+    ) -> Result<(), PrintError>;
 
-    fn print_const(self, ct: ty::Const<'tcx>) -> Result<Self, PrintError>;
+    fn print_const(&mut self, ct: ty::Const<'tcx>) -> Result<(), PrintError>;
 
-    fn path_crate(self, cnum: CrateNum) -> Result<Self, PrintError>;
+    fn path_crate(&mut self, cnum: CrateNum) -> Result<(), PrintError>;
 
     fn path_qualified(
-        self,
+        &mut self,
         self_ty: Ty<'tcx>,
         trait_ref: Option<ty::TraitRef<'tcx>>,
-    ) -> Result<Self, PrintError>;
+    ) -> Result<(), PrintError>;
 
     fn path_append_impl(
-        self,
-        print_prefix: impl FnOnce(Self) -> Result<Self, PrintError>,
+        &mut self,
+        print_prefix: impl FnOnce(Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
         self_ty: Ty<'tcx>,
         trait_ref: Option<ty::TraitRef<'tcx>>,
-    ) -> Result<Self, PrintError>;
+    ) -> Result<(), PrintError>;
 
     fn path_append(
-        self,
-        print_prefix: impl FnOnce(Self) -> Result<Self, PrintError>,
+        &mut self,
+        print_prefix: impl FnOnce(Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
-    ) -> Result<Self, PrintError>;
+    ) -> Result<(), PrintError>;
 
     fn path_generic_args(
-        self,
-        print_prefix: impl FnOnce(Self) -> Result<Self, PrintError>,
+        &mut self,
+        print_prefix: impl FnOnce(Self) -> Result<(), PrintError>,
         args: &[GenericArg<'tcx>],
-    ) -> Result<Self, PrintError>;
+    ) -> Result<(), PrintError>;
 
     // Defaults (should not be overridden):
 
     #[instrument(skip(self), level = "debug")]
     fn default_print_def_path(
-        self,
+        &mut self,
         def_id: DefId,
         args: &'tcx [GenericArg<'tcx>],
-    ) -> Result<Self, PrintError> {
+    ) -> Result<(), PrintError> {
         let key = self.tcx().def_key(def_id);
         debug!(?key);
 
@@ -180,12 +180,12 @@ pub trait Printer<'tcx>: Sized {
     }
 
     fn default_print_impl_path(
-        self,
+        &mut self,
         impl_def_id: DefId,
         _args: &'tcx [GenericArg<'tcx>],
         self_ty: Ty<'tcx>,
         impl_trait_ref: Option<ty::TraitRef<'tcx>>,
-    ) -> Result<Self, PrintError> {
+    ) -> Result<(), PrintError> {
         debug!(
             "default_print_impl_path: impl_def_id={:?}, self_ty={}, impl_trait_ref={:?}",
             impl_def_id, self_ty, impl_trait_ref