Build errors with nightly?

[ornamentist]

Apologies if this is a non-error, I'm still learning to use the Rust development tools.

When I cargo build my project that uses interpolate_idents I see:

error[E0624]: method `span_err` is private  --> /foo/.cargo/registry/src/github.com-1ecc6299db9ec823/interpolate_idents-0.2.4/src/parser_any_macro.rs:54:20
   |
54 |             parser.span_err(span, &msg[..]);
   |

And

error[E0624]: method `parse_impl_item` is private  --> /foo/.cargo/registry/src/github.com-1ecc6299db9ec823/interpolate_idents-0.2.4/src/parser_any_macro.rs:86:48
   |
86 |                 _ => ret.push(panictry!(parser.parse_impl_item(&mut false)))
   |

With:

$ ~/.cargo/bin/cargo --version
cargo 1.28.0-nightly (e2348c2db 2018-06-07)

[ornamentist]

Much appreciated.