Stack overflow from closure TAIT in a method on the opaque type itself in debug mode #144832
Description
Code
#![feature(type_alias_impl_trait)] type Opaque = impl Sized; trait Trait { fn foo(); } impl Trait for Opaque { #[define_opaque(Opaque)] fn foo() { let _: Opaque = || {}; } } fn main() { Opaque::foo(); }@rustbot labels +F-type_alias_impl_trait +I-crash
Crash only occurs when compiling in debug mode
Possibly related to #136390
Meta
Reproducible on the playground with version version: 1.90.0-nightly (2025-08-01 4b55fe199cfe9c710555)
Error output
error: rustc interrupted by SIGSEGV, printing backtrace Backtrace
/playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x3c8efcf)[0x7e5504e8efcf] /lib/x86_64-linux-gnu/libc.so.6(+0x45330)[0x7e550102e330] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x67e3c7c)[0x7e55079e3c7c] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e2959d)[0x7e550702959d] ### cycle encountered after 4 frames with period 6 /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e256f8)[0x7e55070256f8] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e256f8)[0x7e55070256f8] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e29171)[0x7e5507029171] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e256f8)[0x7e55070256f8] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e256f8)[0x7e55070256f8] /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/librustc_driver-2a52e13f9d86ed3d.so(+0x5e29171)[0x7e5507029171] ### recursed 42 times note: rustc unexpectedly overflowed its stack! this is a bug note: maximum backtrace depth reached, frames may have been lost note: we would appreciate a report at https://github.com/rust-lang/rust help: you can increase rustc's stack size by setting RUST_MIN_STACK=16777216 error: could not compile `playground` (bin "playground")