1 files changed, 14 insertions, 5 deletions
diff --git a/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
index ded0888c3..bfe95852a 100644
--- a/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
+++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/record_consumed_borrow.rs
@@ -1,13 +1,16 @@
 use super::TrackedValue;
 use crate::{
-    check::FnCtxt,
     expr_use_visitor::{self, ExprUseVisitor},
+    FnCtxt,
 };
 use hir::{def_id::DefId, Body, HirId, HirIdMap};
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
-use rustc_middle::hir::place::{PlaceBase, Projection, ProjectionKind};
 use rustc_middle::ty::{ParamEnv, TyCtxt};
+use rustc_middle::{
+    hir::place::{PlaceBase, Projection, ProjectionKind},
+    ty::TypeVisitable,
+};
 
 pub(super) fn find_consumed_and_borrowed<'a, 'tcx>(
     fcx: &'a FnCtxt<'a, 'tcx>,
@@ -159,8 +162,8 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
         bk: rustc_middle::ty::BorrowKind,
     ) {
         debug!(
-            "borrow: place_with_id = {place_with_id:?}, diag_expr_id={diag_expr_id:?}, \
-            borrow_kind={bk:?}"
+            "borrow: place_with_id = {place_with_id:#?}, diag_expr_id={diag_expr_id:#?}, \
+            borrow_kind={bk:#?}"
         );
 
         self.borrow_place(place_with_id);
@@ -198,7 +201,13 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
 
         // If the type being assigned needs dropped, then the mutation counts as a borrow
         // since it is essentially doing `Drop::drop(&mut x); x = new_value;`.
-        if assignee_place.place.base_ty.needs_drop(self.tcx, self.param_env) {
+        let ty = self.tcx.erase_regions(assignee_place.place.base_ty);
+        if ty.needs_infer() {
+            self.tcx.sess.delay_span_bug(
+                self.tcx.hir().span(assignee_place.hir_id),
+                &format!("inference variables in {ty}"),
+            );
+        } else if ty.needs_drop(self.tcx, self.param_env) {
             self.places
                 .borrowed
                 .insert(TrackedValue::from_place_with_projections_allowed(assignee_place));