Using systemwide clang and libcxx, I can no longer build webkit-gtk: /usr/include/c++/v1/__algorithm/iterator_operations.h:100:5: error: static assertion failed due to requirement 'is_same<JSC::UnlinkedCallLinkInfo &, const JSC::UnlinkedCallLinkInfo &>::value': It looks like your iterator's `iterator_traits<It>::reference` does not match the return type of dereferencing the iterator, i.e., calling `*it`. This is undefined behavior according to [input.iterators] and can lead to dangling reference issues at runtime, so we are flagging this. static_assert(is_same<__deref_t<_Iter>, typename iterator_traits<__uncvref_t<_Iter> >::reference>::value, ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /usr/include/c++/v1/__algorithm/iterator_operations.h:115:5: note: in instantiation of function template specialization 'std::_IterOps<std::_ClassicAlgPolicy>::__validate_iter_reference<WTF::SegmentedVectorIterator<JSC::UnlinkedCallLinkInfo, 8> &>' requested here __validate_iter_reference<_Iter>(); ^ Switching the standard library to GNU libstdc++ fixes the problem (even if the compiler remains clang). Reproducible: Always Steps to Reproduce: 1. Set up your toolchain to use libcxx-15 instead of libstdc++ 2. Try to build webkit-gtk 3. Profit Actual Results: Fails to compile. Expected Results: Should compile.
Created attachment 813238 [details] build.log
Created attachment 813241 [details] emerge --info
Could you report this upstream? I had a quick skim on https://bugs.webkit.org but couldn't see this bug there yet. I don't see a patch in FreeBSD either (great place to check for libc++ issues, if you haven't already been checking there btw!)
https://bugs.webkit.org/show_bug.cgi?id=245574
Apprently fixed upstream: https://bugs.webkit.org/show_bug.cgi?id=245183 https://github.com/WebKit/WebKit/pull/4339 (not confirmed from my end yet)
Looks like the commit is in tag webkitgtk-2.39.1. It was cherry-picked to the webkitglib/2.38 branch as commit 762ab19c8d323fcb47bb34df7c85a0a4d016b9ed and was included in webkitgtk-2.38.1.
