Document *args and **kwargs restriction in BUILD files
RELNOTES: None.
@@ -459,7 +459,9 @@ cc_binary(
contain function definitions, <code>for</code> statements or
<code>if</code> statements (but list comprehensions and <code>if</code>
expressions are allowed). Functions should be declared in <code>.bzl</code>
- files instead.
+ files instead. Additionally, <code>*args</code> and <code>**kwargs</code>
+ arguments are not allowed in BUILD files; instead list all the arguments
+ explicitly.
</p>
<p>
