Compilation error with syn 1.0.58 and later

I'm using commit d8e4517fb38f617b23cb050955ad8038342d6f31 (current master). The new syn version (1.0.60 in my case) breaks compilation of xtr. According to this analysis it was syn 1.0.58, which introduced a backwards-incompatible change. I didn't check any further.

error[E0432]: unresolved import `syn::export`
  --> xtr/src/main.rs:25:10
   |
25 | use syn::export::ToTokens;
   |          ^^^^^^ could not find `export` in `syn`

error[E0599]: no method named `into_token_stream` found for reference `&syn::File` in the current scope
   --> xtr/src/main.rs:266:22
    |
266 |                 file.into_token_stream(),
    |                      ^^^^^^^^^^^^^^^^^ method not found in `&syn::File`

I'm not a Rust programmer and worked around it by specifying 1.0.55, <1.0.56 as the syn dependency version in the xtr/Cargo.toml, since I had version 1.0.55 already laying around locally.

woboq / tr

Compilation error with syn 1.0.58 and later #8