Compiling the following program:

import java.util.*;

class Test {

    <T> Comparator<T> compound(Iterable<? extends Comparator<? super T>> it) {}

    public void test(List<Comparator<?>> x) {
        Comparator<String> c3 = compound(x);
    }
}

leads to the following compiler error message:

TestX.java:9: invalid inferred types for T#1; actual arguments do not conforms to inferred formal arguments
        Comparator<String> c3 = compound(x);
                                        ^
    required: Iterable<? extends Comparator<? super String>>
    found: List<Comparator<?>>
  where T#1,T#2 are type-variables:
    T#1 extends Object declared in method <T#2>compound(Iterable<? extends Comparator<? super T#2>>)
    T#2 extends Object declared in method <T#2>compound(Iterable<? extends Comparator<? super T#2>>)
1 error

The error message should be:

TestX.java:9: invalid inferred types for T; actual arguments do not conforms to inferred formal arguments
        Comparator<String> c3 = compound(x);
                                        ^
    required: Iterable<? extends Comparator<? super String>>
    found: List<Comparator<?>>
  where T is a type-variable:
    T extends Object declared in method <T>compound(Iterable<? extends Comparator<? super T>>)
Moreover, when compiling the following example:

class Foo<T extends String, S> {
   <S, T extends S> void foo(T t) {
      test(t);
   }

   void test(T t) {}
}

The output is:

TestX.java:3: method test in class Foo<T#1,S#4> cannot be applied to given types
      test(t);
      ^
  required: T#1
  found: T#2
  where T#1,T#2,S#3,S#4 are type-variables:
    T#1 extends String declared in class Foo
    T#2 extends S#3 declared in method <S#3,T#2>foo(T#2)
    S#3 extends Object declared in method <S#3,T#2>foo(T#2)
    S#4 extends Object declared in class Foo
1 error

When it should have been:

TestX.java:3: method test in class Foo<T#1,S#4> cannot be applied to given types
  test(t);
      ^
  required: T#1
  found: T#2
  where T#1,T#2,S#1,S#2 are type-variables:
    T#1 extends String declared in class Foo
    T#2 extends S#1 declared in method <S#1,T#2>foo(T#2)
    S#1 extends Object declared in method <S#1,T#2>foo(T#2)
    S#2 extends Object declared in class Foo
1 error

[note the wrong numbering of type-variables in the where clause!]