Imprecise error message when parameter type is missing

[cryptocode]

Zig Version

0.10.0-dev.4587+710e2e7f1

Steps to Reproduce and Observed Behavior

When the type is missing:

fn func(comptime x) u64 {
    return x * 2;
}

...then the error message says the parameter name is missing, rather than the parameter type.

error: missing parameter name

Expected Behavior

Sometimes the current error message happens to make sense, i.e. when the programmer puts a type name there.

However, since type annotations require : I expected the error to say missing parameter type in this example.

Rust offers the following elaboration:

...
help: if this is a `self` type, give it a parameter name
  |
1 | fn func(self: x) -> u64 {
  |         +++++
help: if this is a parameter name, give it a type
  |
1 | fn func(x: TypeName) -> u64 {
  |          ++++++++++
help: if this is a type, explicitly ignore the parameter name
  |
1 | fn func(_: x) -> u64 {