force_fallback produce invalid span

[zzau13]

In [email protected], related zzau13/yarte#211

With parse impl of syn::Expr:

ywrite_html!(buf, "{{ @ }}");

works correctly, error is spammed by syn with fallback span.

And for this with Punctuated::parse_terminated:

ywrite_html!(buf, r#"{{> hello_ex my_card body="foo" }}"#);

not works, panic with Invalid span with no related FileInfo!

[dtolnay]

Would you be able to provide a minimal repro using proc-macro2 only, independent of yarte and syn?

[zzau13]

It is much more complicated than I expected, I cannot replicate it separately. It will take a little longer.

The implementation is very stable but from the error messages it seems that it operates with both types of Span when it should be forced to fallback.

I will try to reproduce it but it will take a little longer.

[dtolnay]

I'll close this in the absence of a way to reproduce. Feel free to open a new issue if you nail down what's happening.