Redirected constructor is undefinedDRT-W1586

The analyzer produces this diagnostic when a generative constructor redirects to a constructor that isn't defined.

Example

The following code produces this diagnostic because the constructor C.a redirects to the constructor C.b, but C.b isn't defined:

class C {
  C.a() : this.b();
}

Common fixes

If the missing constructor must be called, then define it:

class C {
  C.a() : this.b();
  C.b();
}

If the missing constructor doesn't need to be called, then remove the redirect:

class C {
  C.a();
}