$ cat -n Test.java
     1  class Test {
     2      public static void foo(int ...i) {}
     3      public static void foo(double...d) {}
     4
     5      public static void main(String[] args) {
     6          foo(1, 2, 3);
     7      }
     8  }
     9
$ javac Test.java
Test.java:6: reference to foo is ambiguous, both method foo(int...) in Test and method foo(double...) in Test match
        foo(1, 2, 3);
        ^
1 error

Javac is incorrect since int <: double which makes foo(int...) more specific than foo(double...).