A structure-literal syntax was used to create an item that is not a structure or enum variant.
Example of erroneous code:
type U32 = u32;
let t = U32 { value: 4 }; // error: expected struct, variant or union type,
// found builtin type `u32`
To fix this, ensure that the name was correctly spelled, and that the correct form of initializer was used.
For example, the code above can be fixed to:
type U32 = u32;
let t: U32 = 4;
or:
struct U32 { value: u32 }
let t = U32 { value: 4 };