dead_code_catch_following_catch

Dead code: Catch clauses after a 'catch (e)' or an 'on Object catch (e)' are never reached.

The analyzer produces this diagnostic when a catch clause is found that can't be executed because it's after a catch clause of the form catch (e) or on Object catch (e). The first catch clause that matches the thrown object is selected, and both of those forms will match any object, so no catch clauses that follow them will be selected.

The following code produces this diagnostic:

void f() {
  try {
    // ...
  } catch (e) {
    // Not reached.
  } on String {
    // ...
  }
}

If the clause should be selectable, then move the clause before the general clause:

void f() {
  try {
    // ...
  } on String {
    // ...
  } catch (e) {
    // ...
  }
}

If the clause doesn't need to be selectable, then remove it:

void f() {
  try {
    // ...
  } catch (e) {
    // ...
  }
}