This is being emitted with [GCC 10.2.1](https://packages.debian.org/bullseye/g++-arm-linux-gnueabihf), in some CI jobs: i.e https://github.com/bitcoin/bitcoin/pull/25972/checks?check_run_id=12423693655, or https://github.com/bitcoin/bitcoin/pull/25972/checks?check_run_id=12423693651 (where we actually turn on all our warning flags with depends builds).
```bash
In file included from test/miniscript_tests.cpp:19:
./script/miniscript.h:1197:71: error: comparison of integers of different signs: 'typename iterator_traits<int *>::difference_type' (aka 'int') and 'const uint32_t' (aka 'const unsigned int') [-Werror,-Wsign-compare]
                    return std::count(subs.begin(), subs.end(), true) >= node.k;
                           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~~~~~
test/miniscript_tests.cpp:346:34: note: in instantiation of function template specialization 'miniscript::Node<CPubKey>::IsSatisfiable<(lambda at test/miniscript_tests.cpp:346:48)>' requested here
        bool satisfiable = node->IsSatisfiable([](const Node&) { return true; });
                                 ^
1 error generated.
```

cc @darosior 
}
            }
            
            
            size_t keys_count = node.keys.size();
            keyset key_set{node.keys.begin(), node.keys.end(), Comp(ctx)};
            if (key_set.size() != keys_count) {
                
                node.has_duplicate_keys = true;
                return {};
            }
            
            for (auto& sub : subs) {
                keys_count += sub->size();
                
                
                if (key_set.size() < sub->size()) std::swap(key_set, *sub);
                key_set.merge(*sub);
                if (key_set.size() != keys_count) {
                    node.has_duplicate_keys = true;
                    return {};
                }
            }
            node.has_duplicate_keys = false;
            return key_set;
        };
        TreeEval<state>(upfn);
    }
    
    size_t ScriptSize() const { return scriptlen; }