First error in log looks like:
:info:build /opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_macports_release_tarballs_ports_lang_rust/rust/work/rustc-1.78.0-src/src/llvm-project/llvm/lib/Support/Program.cpp:46:49: error: no viable constructor or deduction guide for deduction of template arguments of 'optional'
:info:build PI, SecondsToWait == 0 ? std::nullopt : std::optional(SecondsToWait),
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:684:41: note: candidate template ignored: couldn't infer template argument '_Tp'
:info:build _LIBCPP_INLINE_VISIBILITY constexpr optional(nullopt_t) noexcept {}
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:690:24: note: candidate template ignored: couldn't infer template argument '_Tp'
:info:build constexpr explicit optional(in_place_t, _Args&&... __args)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:704:15: note: candidate template ignored: couldn't infer template argument '_Tp'
:info:build constexpr optional(_Up&& __v)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:711:24: note: candidate template ignored: couldn't infer template argument '_Tp'
:info:build constexpr explicit optional(_Up&& __v)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:580:7: note: candidate template ignored: could not match 'optional<_Tp>' against 'unsigned int'
:info:build class optional
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:682:41: note: candidate template ignored: could not match 'optional<_Tp>' against 'unsigned int'
:info:build _LIBCPP_INLINE_VISIBILITY constexpr optional(const optional&) = default;
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:683:41: note: candidate template ignored: could not match 'optional<_Tp>' against 'unsigned int'
:info:build _LIBCPP_INLINE_VISIBILITY constexpr optional(optional&&) = default;
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:719:5: note: candidate template ignored: could not match 'optional<type-parameter-0-1>' against 'unsigned int'
:info:build optional(const optional<_Up>& __v)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:727:14: note: candidate template ignored: could not match 'optional<type-parameter-0-1>' against 'unsigned int'
:info:build explicit optional(const optional<_Up>& __v)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:737:5: note: candidate template ignored: could not match 'optional<type-parameter-0-1>' against 'unsigned int'
:info:build optional(optional<_Up>&& __v)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:745:14: note: candidate template ignored: could not match 'optional<type-parameter-0-1>' against 'unsigned int'
:info:build explicit optional(optional<_Up>&& __v)
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:681:41: note: candidate function template not viable: requires 0 arguments, but 1 was provided
:info:build _LIBCPP_INLINE_VISIBILITY constexpr optional() noexcept {}
:info:build ^
:info:build /Library/Developer/CommandLineTools/usr/include/c++/v1/optional:697:24: note: candidate function template not viable: requires at least 2 arguments, but 1 was provided
:info:build constexpr explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
:info:build ^
:info:build 1 error generated.
