https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66924
--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note the "parse error" part of the diagnostic is no longer there on the trunk
(for GCC 14).
clang produces:
```
<source>:6:46: error: non-type template argument is not a constant expression
6 | auto f = [] (int x) -> decltype(variable<x>) {return{};};
| ^
<source>:6:46: note: function parameter 'x' with unknown value cannot be used
in a constant expression
<source>:6:22: note: declared here
6 | auto f = [] (int x) -> decltype(variable<x>) {return{};};
| ^
```
