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 
using namespace internal;
        
        
        auto helper = [&ctx](const Node& node, Span<InputResult> subres) -> InputResult {
            switch (node.fragment) {
                case Fragment::PK_K: {
                    std::vector<unsigned char> sig;
                    Availability avail = ctx.Sign(node.keys[0], sig);
                    return {ZERO, InputStack(std::move(sig)).SetWithSig().SetAvailable(avail)};
                }
                case Fragment::PK_H: {
                    std::vector<unsigned char> key = ctx.ToPKBytes(node.keys[0]), sig;
                    Availability avail = ctx.Sign(node.keys[0], sig);
                    return {ZERO + InputStack(key), (InputStack(std::move(sig)).SetWithSig() + InputStack(key)).SetAvailable(avail)};
                }
                case Fragment::MULTI: {
                    
                    
                    
                    std::vector<InputStack> sats = Vector(ZERO);
                    for (size_t i = 0; i < node.keys.size(); ++i) {
                        std::vector<unsigned char> sig;