Compile Error When Wrapping Receiver by Derivation

Reproduce the failure with the sender and receiver example, using the attached build.log as the expected diagnostic. Start at include/stdexec/__detail/__basic_sender.hpp line 362 and trace how the derived receiver type is used when connecting the operation. Done means the example compiles without confusing the derived receiver with its base type.

Given:

template<::stdexec::receiver Receiver>
struct receiver : Receiver {
  template<typename T>
    requires std::constructible_from<Receiver, T>
  explicit constexpr receiver(T&& t) noexcept(
    std::is_nothrow_constructible_v<Receiver, T>)
    : Receiver(std::forward<T>(t))
  {}
};

template<::stdexec::sender Sender>
struct sender {
  using sender_concept = ::stdexec::sender_t;
  template<typename T>
    requires std::constructible_from<Sender, T>
  explicit constexpr sender(T&& t) noexcept(
    std::is_nothrow_constructible_v<Sender, T>)
    : sender_(std::forward<T>(t))
  {}
  template<typename Self, typename Env>
  ::stdexec::completion_signatures_of_t<
    decltype(std::declval<Self>().sender_),
    Env> get_completion_signatures(this Self&&, const Env&);
  template<typename Self, typename Receiver>
    requires ::stdexec::sender_to<
      Sender,
      receiver<std::remove_cvref_t<Receiver>>>
  auto connect(this Self&& self, Receiver&& r) noexcept(
    noexcept(
      ::stdexec::connect(
        std::declval<Self>().sender_,
        receiver<std::remove_cvref_t<Receiver>>(std::declval<Receiver>()))))
  {
    return ::stdexec::connect(
      std::forward<Self>(self).sender_,
      receiver<std::remove_cvref_t<Receiver>>(std::forward<Receiver>(r)));
  }
private:
  Sender sender_;
};

template<typename T>
explicit sender(T) -> sender<T>;

The following fails to compile (at least on GCC 14.1.0):

auto op = ::stdexec::connect(
  ::stdexec::just() | ::stdexec::let_value([]() {
    return sender(
      ::stdexec::just() | ::stdexec::then([]() noexcept {
        return 5;
      }));
  }),
  make_receiver([](auto&&...) noexcept {}));

Where the make_receiver invocation simply creates a receiver that accepts anything.

Internally the machinery seems to be confusing the derived type with the base type:

/scratch/mdx/src/../include/stdexec/__detail/__basic_sender.hpp:362:84: error: cannot convert ‘stdexec::__detail::__op_state<stdexec::__sexpr<<lambda closure object>stdexec::{anonymous}::<lambda()>(), stdexec::{anonymous}::__anon>, mdx::execution::tests::{anonymous}::receiver<stdexec::__any_::__receiver_ref<stdexec::completion_signatures<stdexec::__rcvrs::set_value_t(int)> > > >* const’ to ‘stdexec::__detail::__receiver<stdexec::__any_::__receiver_ref<stdexec::completion_signatures<stdexec::__rcvrs::set_value_t(int)> >, stdexec::__sexpr<<lambda closure object>stdexec::{anonymous}::<lambda()>(), stdexec::{anonymous}::__anon>, stdexec::__muchar (*)[1]>::__t::__parent_op_t*’ {aka ‘stdexec::__detail::__op_state<stdexec::__sexpr<<lambda closure object>stdexec::{anonymous}::<lambda()>(), stdexec::{anonymous}::__anon>, stdexec::__any_::__receiver_ref<stdexec::completion_signatures<stdexec::__rcvrs::set_value_t(int)> > >*’} in initialization
  362 |           return __tuple{connect(static_cast<_Child&&>(__child), __receiver_t<_Is>{__op_})...};
      |                                                                                    ^~~~~
      |                                                                                    |
      |                                                                                    stdexec::__detail::__op_state<stdexec::__sexpr<<lambda closure object>stdexec::{anonymous}::<lambda()>(), stdexec::{anonymous}::__anon>, mdx::execution::tests::{anonymous}::receiver<stdexec::__any_::__receiver_ref<stdexec::completion_signatures<stdexec::__rcvrs::set_value_t(int)> > > >* const

Full compilation output attached.

build.log