Regression between 2.7.0 and 2.8.1 around # operator in slog macros (tuple struct constructor ErrorTagWrapper is private) #364
Description
use std::io::Error;
use slog::Logger;
fn repro(log: Logger) {
let err = Error::other("some error");
slog::info!(log, "oops"; "err" => #err);
}This compiles successfully on 2.7.0, but fails on 2.8.1 with this error:
Checking slog-test v0.1.0 (/home/manishearth/sand/crates/slog-test)
error[E0603]: tuple struct constructor `ErrorTagWrapper` is private
--> /home/manishearth/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/slog-2.8.1/src/lib.rs:920:25
|
920 | let w = $crate::ErrorTagWrapper(v);
| ^^^^^^^^^^^^^^^ private tuple struct constructor
...
3544 | pub struct ErrorTagWrapper<E>(E);
| - a constructor is private if any of the fields is private
|
::: src/lib.rs:6:5
|
6 | slog::info!(log, "oops"; "err" => #err);
| --------------------------------------- tuple struct `ErrorTagWrapper` is not publicly re-exported
|
note: the tuple struct constructor `ErrorTagWrapper` is defined here
--> /home/manishearth/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/slog-2.8.1/src/lib.rs:3544:1
|
3544 | pub struct ErrorTagWrapper<E>(E);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error[E0616]: field `0` of struct `ErrorTagWrapper` is private
--> src/lib.rs:6:5
|
6 | slog::info!(log, "oops"; "err" => #err);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ private field
|
= note: this error originates in the macro `$crate::__builtin` which comes from the expansion of the macro `slog::info` (in Nightly builds, run with -Z macro-backtrace for more info)