Constrain generated signature for nondiff frule to need tuple first arg so no ambig with ruleconfig first arg

Author: oxinabox

src/rule_definition_tools.jl

@@ -403,13 +403,13 @@ function _nondiff_frule_expr(__source__, primal_sig_parts, primal_invoke)
         function (::Core.kwftype(typeof(ChainRulesCore.frule)))(
             @nospecialize($kwargs::Any),
             frule::typeof(ChainRulesCore.frule),
-            ::$RuleConfig,
+            ::Tuple,
             $(map(esc, primal_sig_parts)...),
         )
             return ($(esc(_with_kwargs_expr(primal_invoke, kwargs))), NoTangent())
         end
         function ChainRulesCore.frule(
-            ::$RuleConfig, $(map(esc, primal_sig_parts)...)
+            ::Tuple, $(map(esc, primal_sig_parts)...)
         )
             $(__source__)
             # Julia functions always only have 1 output, so return a single NoTangent()

test/rule_definition_tools.jl

@@ -220,14 +220,14 @@ end
 
             foo_ndc1(x) = string(x)
             @non_differentiable foo_ndc1(x)
-            @test frule(AllConfig(), foo_ndc1, 2.0) == (string(2.0), NoTangent())
+            @test frule(AllConfig(), (NoTangent(), NoTangent()), foo_ndc1, 2.0) == (string(2.0), NoTangent())
             r1, pb1 = rrule(AllConfig(), foo_ndc1, 2.0)
             @test r1 == string(2.0)
             @test pb1(NoTangent()) == (NoTangent(), NoTangent())
 
             foo_ndc2(x; y=0) = string(x + y)
             @non_differentiable foo_ndc2(x)
-            @test frule(AllConfig(), foo_ndc2, 2.0; y=4.0) == (string(6.0), NoTangent())
+            @test frule(AllConfig(), (NoTangent(), NoTangent()), foo_ndc2, 2.0; y=4.0) == (string(6.0), NoTangent())
             r2, pb2 = rrule(AllConfig(), foo_ndc2, 2.0; y=4.0)
             @test r2 == string(6.0)
             @test pb2(NoTangent()) == (NoTangent(), NoTangent())