Strange warning with latest nighly

1

Hello all.

I have strange warning during compilation of mockers tests with latest nighly:

   Compiling mockers_macros v0.4.6 (file:///Users/kriomant/Dropbox/Projects/mockers/mockers_macros)
warning: empty trait list in `derive`
  --> tests/derive.rs:10:3
   |
10 | #[derive(Mock)]
   |   ^^^^^^^^^^^^

What does it mean? Trait list is definitely not empty.

2

I'm getting the same warning.

warning: empty trait list in derive
--> src/main.rs:78:3
|
78 | #[derive(ToJson)]
| ^^^^^^^^^^^^^^

3

Fixed in https://github.com/rust-lang/rust/pull/37034