https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95111
--- Comment #1 from Iain Sandoe <iains at gcc dot gnu.org> --- There are some gotchas with coroutines and references (both regular and rvalue). * there could still be a bug here, so I want to double-check. Please could you expand your snippets of code into a small test-case that would would expect to work? (FWIW, in my original impl. I tried to be more defensive about lambda captures - but that wasn't correct in the presence of a mutable lambda - and didn't agree with other implementations - or the collective understanding of the intent of the standard - so I backed that out).