[  8%] Building CXX object src/shogun/CMakeFiles/libshogun.dir/classifier/vw/cache/VwCacheReader.cpp.o
In file included from /build/source/build/src/shogun/lib/external/rxcpp/rx-includes.hpp:174,
                 from /build/source/build/src/shogun/lib/external/rxcpp/rx-lite.hpp:9,
                 from /build/source/src/shogun/base/init.cpp:21:
/build/source/build/src/shogun/lib/external/rxcpp/rx-notification.hpp: In member function 'rxcpp::notifications::notification<T>::on_error_notification& rxcpp::notifications::notification<T>::on_error_notification::operator=(rxcpp::notifications::notification<T>::on_error_notification)':
/build/source/build/src/shogun/lib/external/rxcpp/rx-notification.hpp:153:88: error: no match for 'operator=' (operand types are 'const std::__exception_ptr::exception_ptr' and 'std::remove_reference<const std::__exception_ptr::exception_ptr&>::type' {aka 'const std::__exception_ptr::exception_ptr'})
  153 |         on_error_notification& operator=(on_error_notification o) { ep = std::move(o.ep); return *this; }
      |                                                                                        ^
In file included from /nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/exception:166,
                 from /nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/ios:41,
                 from /nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/istream:40,
                 from /nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/sstream:40,
                 from /nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/complex:45,
                 from /build/source/src/shogun/lib/common.h:75,
                 from /build/source/src/shogun/lib/memory.h:15,
                 from /build/source/src/shogun/base/init.cpp:12:
/nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/bits/exception_ptr.h:212:5: note: candidate: 'std::__exception_ptr::exception_ptr& std::__exception_ptr::exception_ptr::operator=(const std::__exception_ptr::exception_ptr&)' (near match)
  212 |     exception_ptr::operator=(const exception_ptr& __other) _GLIBCXX_USE_NOEXCEPT
      |     ^~~~~~~~~~~~~
/nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/bits/exception_ptr.h:212:5: note:   passing 'const std::__exception_ptr::exception_ptr*' as 'this' argument discards qualifiers
/nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/bits/exception_ptr.h:140:7: note: candidate: 'std::__exception_ptr::exception_ptr& std::__exception_ptr::exception_ptr::operator=(std::__exception_ptr::exception_ptr&&)' (near match)
  140 |       operator=(exception_ptr&& __o) noexcept
      |       ^~~~~~~~
/nix/store/sa7j7cddyblhcb3ch3ds10w7nw75yjj1-gcc-14.3.0/include/c++/14.3.0/bits/exception_ptr.h:140:7: note:   conversion of argument 1 would be ill-formed: