public struct in framework init is inaccessible due to ‘internal’ protection level in compiler

Lesson learned: all public struct need a public init

That’s not quite exact. The documentation states:

Default Memberwise Initializers for Structure Types

The default memberwise initializer for a structure type is considered private if any of the structure’s stored properties are private. Likewise, if any of the structure’s stored properties are file private, the initializer is file private. Otherwise, the initializer has an access level of internal.

So the build-in memberwise initializer is only available within the package. If you don’t provide a public initializer, you won’t be able to create your struct from outer space.

public struct YourFrameworkStruct {
    let frameworkStructProperty: String!
    /// Your public structs in your framework need a public init.
    /// 
    /// Don't forget to add your let properties initial values too.
    public init(frameworkStructProperty: String) {
        self.frameworkStructProperty = frameworkStructProperty
    }
}