Enabling "nightly" feature breaks processing of mod in another file

[CodeSandwich]

Situation

my_mod is a module with body in file my_mod.rs. To include it in the project it must be declared in another file, let's say lib.rs. I'm trying to push whole my_mod into proc macro my_macro, so I write in lib.rs:

#[my_macro]
mod my_mod;

Without "nightly" feature

Whole content of my_mod is passed into macro.

With "nightly" feature

Only mod my_mod; is passed into macro.

Question

Is it regression or is it the way proc macros 2.0 are supposed to work?

[mystor]

This sounds like a rustc issue - I'm not sure. It's surprising that the to_string method would produce such a dramatically different result than the TokenStream.

[dtolnay]

I don't think we can fix this in proc-macro2 so I filed rust-lang/rust#47627 to follow up in the compiler. Thanks!

[CodeSandwich]

Thank you for investigation and filing a root cause issue!