error[E0080]: evaluation of constant value failed
 --> src/lib.rs
  |
  |         [0, _, ..] => panic!("C strings can't contain null bytes"),
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'C strings can't contain null bytes', $DIR/src/lib.rs:15:23
  |
note: inside `new`
 --> src/lib.rs
  |
  |         [0, _, ..] => panic!("C strings can't contain null bytes"),
  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
note: inside `__CSTR`
 --> tests/invalid/null.rs:4:3
  |
4 |   cstr!("\0");
  |   ^^^^^^^^^^^
  = note: this error originates in the macro `$crate::panic::panic_2021` which comes from the expansion of the macro `cstr` (in Nightly builds, run with -Z macro-backtrace for more info)