https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97052
David Stone <david at doublewise dot net> changed:
What |Removed |Added
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CC| |david at doublewise dot net
--- Comment #2 from David Stone <david at doublewise dot net> ---
Turns out the substitution failure is a red herring. Here is a simpler
reproduction:
```
template<typename T, typename U = typename T::type>
concept foo = true;
void f(foo auto) {
}
```
