Concrete regions can show up in mir borrowck if the originated from there.

We used to not encounter them here, because we took regions from typeck's opaque type resolution by renumbering them. We don't do that anymore.

1 files changed, 1 insertions, 9 deletions

diff --git a/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs b/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs
index e9ab62e1664..12fceeff088 100644
--- a/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs
+++ b/compiler/rustc_mir/src/borrow_check/region_infer/opaque_types.rs
@@ -82,15 +82,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                             .find(|ur_vid| self.eval_equal(vid, **ur_vid))
                             .and_then(|ur_vid| self.definitions[*ur_vid].external_name)
                             .unwrap_or(infcx.tcx.lifetimes.re_root_empty),
-                        ty::ReLateBound(..) => region,
-                        ty::ReStatic => region,
-                        _ => {
-                            infcx.tcx.sess.delay_span_bug(
-                                span,
-                                &format!("unexpected concrete region in borrowck: {:?}", region),
-                            );
-                            region
-                        }
+                        _ => region,
                     });
 
                 debug!(?universal_concrete_type, ?universal_substs);