One more...

Sigh.

hb-ot-kern-table.hh: In member function 'int OT::KernSubTableFormat3<KernSubTableHeader>::get_kerning(hb_codepoint_t, hb_codepoint_t) const':
hb-ot-kern-table.hh:59: error: ambiguous overload for 'operator[]' in 'kernValue[kernIndex[i]]'
hb-ot-kern-table.hh:59: note: candidates are: operator[](T*, int) <built-in>
hb-dsalgs.hh:574: note:                 Type& hb_array_t<Type>::operator[](unsigned int) const [with Type = const OT::IntType<short int, 2u>]

src/hb-ot-kern-table.hh

@@ -56,7 +56,7 @@ struct KernSubTableFormat3
     if (unlikely (leftC >= leftClassCount || rightC >= rightClassCount))
       return 0;
     unsigned int i = leftC * rightClassCount + rightC;
-    return kernValue[kernIndex[i]];
+    return kernValue[(unsigned) kernIndex[i]];
   }
 
   inline bool apply (AAT::hb_aat_apply_context_t *c) const