diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index ae31ed5939174..e4a733fcbce88 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -1509,6 +1509,13 @@ impl<'v> RootCollector<'_, 'v> { } _ => unreachable!(), }; + let Ok(instance) = self.tcx.try_normalize_erasing_regions( + ty::TypingEnv::fully_monomorphized(), + instance, + ) else { + // Don't ICE on an impossible-to-normalize closure. + return; + }; let mono_item = create_fn_mono_item(self.tcx, instance, DUMMY_SP); if mono_item.node.is_instantiable(self.tcx) { self.output.push(mono_item); diff --git a/tests/ui/closures/eager-mono-with-normalizable-upvars.rs b/tests/ui/closures/eager-mono-with-normalizable-upvars.rs new file mode 100644 index 0000000000000..4d934f7a7a9ad --- /dev/null +++ b/tests/ui/closures/eager-mono-with-normalizable-upvars.rs @@ -0,0 +1,19 @@ +//@ compile-flags: -Clink-dead-code -Csymbol-mangling-version=v0 +//@ build-pass + +// Ensure that when eagerly collecting `test::{closure#0}`, we don't try +// collecting an unnormalized version of the closure (specifically its +// upvars), since the closure captures the RPIT `opaque::{opaque#0}`. + +fn opaque() -> impl Sized {} + +fn test() -> impl FnOnce() { + let opaque = opaque(); + move || { + let opaque = opaque; + } +} + +fn main() { + test()(); +}