error: field index 5 out of range of 2 fields
 --> tests/fail/nightly/derive_placeholders.rs:2:21
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                     ^

error: field `x` does not exist
 --> tests/fail/nightly/derive_placeholders.rs:2:25
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                         ^

error: field `b` has multiple sources
 --> tests/fail/nightly/derive_placeholders.rs:2:34
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                                  ^^^

error: field `b` has multiple sources
 --> tests/fail/nightly/derive_placeholders.rs:2:44
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                                            ^^^

error: too many placeholders
 --> tests/fail/nightly/derive_placeholders.rs:2:31
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                               ^^

error: too many placeholders
 --> tests/fail/nightly/derive_placeholders.rs:2:38
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                                      ^^

error: too many placeholders
 --> tests/fail/nightly/derive_placeholders.rs:2:41
  |
2 | #[sscanf(format = "{5} {x} {} {} {b} {} {} {b}")]
  |                                         ^^

error: field `b` has multiple sources
  --> tests/fail/nightly/derive_placeholders.rs:12:14
   |
12 |     #[sscanf(default = 5)]
   |              ^^^^^^^^^^^

error: field `b` has multiple sources
 --> tests/fail/nightly/derive_placeholders.rs:9:20
  |
9 | #[sscanf(format = "{b}")]
  |                    ^^^

error: FromScanf: field `a` is not specified in the format string and has no default value. You must specify exactly one of these.
       The syntax for default values is: `#[sscanf(default)]` to use Default::default() or `#[sscanf(default = ...)]` to provide a custom value.
  --> tests/fail/nightly/derive_placeholders.rs:11:5
   |
11 |     a: u8,
   |     ^