https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103749
--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I have a patch with which we, for the original test, emit:
$ xg++ -c 103749-2.C
103749-2.C:6:8: error: ‘bar’ was declared as template but no template header
provided
6 | struct bar {
| ^~~
103749-2.C:3:17: note: previous declaration here
3 | friend struct bar;
| ^~~
103749-2.C:10:5: error: ‘bar<...auto...> var’ has incomplete type
10 | bar var;
| ^~~
Hopefully that's a bit better.
