diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index a6d548f19096b..d6704d9e44f9b 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -100,11 +100,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     // Create a type variable (for now) to represent the closure kind.
                     // It will be unified during the upvar inference phase (`upvar.rs`)
-                    None => self.next_ty_var(TypeVariableOrigin {
-                        // FIXME(eddyb) distinguish closure kind inference variables from the rest.
-                        param_def_id: None,
-                        span: expr_span,
-                    }),
+                    None => {
+                        self.next_ty_var(TypeVariableOrigin { param_def_id: None, span: expr_span })
+                    }
                 };
 
                 let closure_args = ty::ClosureArgs::new(
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs
index 6bc81fd6e6f23..c39bc71bd121f 100644
--- a/compiler/rustc_hir_typeck/src/pat.rs
+++ b/compiler/rustc_hir_typeck/src/pat.rs
@@ -1365,13 +1365,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
         let max_len = cmp::max(expected_len, elements.len());
 
-        let element_tys_iter = (0..max_len).map(|_| {
-            self.next_ty_var(
-                // FIXME: `MiscVariable` for now -- obtaining the span and name information
-                // from all tuple elements isn't trivial.
-                TypeVariableOrigin { param_def_id: None, span },
-            )
-        });
+        let element_tys_iter =
+            (0..max_len).map(|_| self.next_ty_var(TypeVariableOrigin { param_def_id: None, span }));
         let element_tys = tcx.mk_type_list_from_iter(element_tys_iter);
         let pat_ty = Ty::new_tup(tcx, element_tys);
         if let Some(err) = self.demand_eqtype_pat_diag(span, expected, pat_ty, pat_info.top_info) {
diff --git a/compiler/rustc_infer/src/infer/opaque_types/mod.rs b/compiler/rustc_infer/src/infer/opaque_types/mod.rs
index cf850353c48d7..94a546f87eee9 100644
--- a/compiler/rustc_infer/src/infer/opaque_types/mod.rs
+++ b/compiler/rustc_infer/src/infer/opaque_types/mod.rs
@@ -65,9 +65,6 @@ impl<'tcx> InferCtxt<'tcx> {
                     let span = if span.contains(def_span) { def_span } else { span };
                     let code = traits::ObligationCauseCode::OpaqueReturnType(None);
                     let cause = ObligationCause::new(span, body_id, code);
-                    // FIXME(compiler-errors): We probably should add a new TypeVariableOriginKind
-                    // for opaque types, and then use that kind to fix the spans for type errors
-                    // that we see later on.
                     let ty_var = self.next_ty_var(TypeVariableOrigin { param_def_id: None, span });
                     obligations.extend(
                         self.handle_opaque_type(ty, ty_var, &cause, param_env).unwrap().obligations,
diff --git a/compiler/rustc_infer/src/infer/type_variable.rs b/compiler/rustc_infer/src/infer/type_variable.rs
index e6cc950ab25b0..96afa257ebbad 100644
--- a/compiler/rustc_infer/src/infer/type_variable.rs
+++ b/compiler/rustc_infer/src/infer/type_variable.rs
@@ -37,7 +37,9 @@ pub struct TypeVariableTable<'a, 'tcx> {
 #[derive(Copy, Clone, Debug)]
 pub struct TypeVariableOrigin {
     pub span: Span,
-    // `DefId` of the type parameter this was instantiated for, if any.
+    /// `DefId` of the type parameter this was instantiated for, if any.
+    ///
+    /// This should only be used for diagnostics.
     pub param_def_id: Option<DefId>,
 }
 
diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
index 870e198d70af2..4b06278330f32 100644
--- a/compiler/rustc_lint/src/non_local_def.rs
+++ b/compiler/rustc_lint/src/non_local_def.rs
@@ -1,9 +1,8 @@
 use rustc_hir::{def::DefKind, Body, Item, ItemKind, Node, TyKind};
 use rustc_hir::{Path, QPath};
-use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_infer::infer::type_variable::TypeVariableOrigin;
 use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::{Obligation, ObligationCause};
-use rustc_middle::query::Key;
 use rustc_middle::ty::{self, Binder, Ty, TyCtxt, TypeFoldable, TypeFolder};
 use rustc_middle::ty::{EarlyBinder, TraitRef, TypeSuperFoldable};
 use rustc_span::def_id::{DefId, LOCAL_CRATE};
@@ -313,13 +312,10 @@ impl<'a, 'tcx, F: FnMut(DefId) -> bool> TypeFolder<TyCtxt<'tcx>>
     }
 
     fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
-        if let Some(ty_did) = t.ty_def_id()
-            && (self.did_has_local_parent)(ty_did)
+        if let Some(def) = t.ty_adt_def()
+            && (self.did_has_local_parent)(def.did())
         {
-            self.infcx.next_ty_var(TypeVariableOrigin {
-                kind: TypeVariableOriginKind::TypeInference,
-                span: self.infer_span,
-            })
+            self.infcx.next_ty_var(TypeVariableOrigin { param_def_id: None, span: self.infer_span })
         } else {
             t.super_fold_with(self)
         }
diff --git a/compiler/rustc_middle/src/infer/unify_key.rs b/compiler/rustc_middle/src/infer/unify_key.rs
index 5280acd72ce7d..105be21f27279 100644
--- a/compiler/rustc_middle/src/infer/unify_key.rs
+++ b/compiler/rustc_middle/src/infer/unify_key.rs
@@ -106,7 +106,9 @@ impl ToType for ty::FloatVarValue {
 #[derive(Copy, Clone, Debug)]
 pub struct ConstVariableOrigin {
     pub span: Span,
-    // `DefId` of the const parameter this was instantiated for, if any.
+    /// `DefId` of the const parameter this was instantiated for, if any.
+    ///
+    /// This should only be used for diagnostics.
     pub param_def_id: Option<DefId>,
 }