The signature of deep_clone is incorrect

[eregon]

ruby-deepclone/ext/deep_clone/deep_clone.c

Line 34 in 465162d

rb_define_module_function(DeepClone, "clone", deep_clone, 1);

ruby-deepclone/ext/deep_clone/deep_clone.c

Line 176 in 465162d

VALUE deep_clone(int argc, VALUE argv)

So the signature of the function deep_clone doesn't match the arity given to rb_define_module_function.
It should be VALUE deep_clone(VALUE self, VALUE arg).

From truffleruby/truffleruby#2073