1 error[E0282]: type annotations needed
2 --> $DIR/issue-16966.rs:12:5
4 LL | panic!(std::default::Default::default());
5 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type for `M`
7 = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
9 error: aborting due to previous error
11 For more information about this error, try `rustc --explain E0282`.