This is a followup to SerenityOS/serenity#23375 (comment)
This patch still needs to be applied to fix the build on NetBSD:

--- Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h.orig     2024-06-06 21:18:50.814506936 +0000
+++ Userland/Libraries/LibGfx/EdgeFlagPathRasterizer.h
@@ -21,7 +21,7 @@ namespace Detail {
 static auto constexpr coverage_lut = [] {
     Array<u8, 256> coverage_lut {};
     for (u32 sample = 0; sample <= 255; sample++)
-        coverage_lut[sample] = popcount(sample);
+        coverage_lut[sample] = AK::popcount(sample);
     return coverage_lut;
 }();

With that patch, I got a working browser that could display github.com (a first for me with ladybird) but when scrolling down, it died with:

(gdb) bt
#0  ak_verification_failed () at /scratch/wip/ladybird-git/work/serenity/AK/Assertions.cpp:108
#1  0x0000000000685b48 in AK::ErrorOr<IPC::File, AK::Error>::release_value_but_fixme_should_propagate_errors () at /scratch/wip/ladybird-git/work/serenity/AK/Error.h:202
#2  Ladybird::WebContentView::initialize_client () at /scratch/wip/ladybird-git/work/serenity/Ladybird/Qt/WebContentView.cpp:571
#3  0x00007817d19169de in WebView::ViewImplementation::handle_web_content_process_crash ()
    at /scratch/wip/ladybird-git/work/serenity/Userland/Libraries/LibWebView/ViewImplementation.cpp:450
#4  0x00007817cd508402 in AK::Function<void ()>::operator()() const () at /scratch/wip/ladybird-git/work/serenity/AK/Function.h:125
#5  0x00007817cd4f68de in Core::ThreadEventQueue::process () at /scratch/wip/ladybird-git/work/serenity/Userland/Libraries/LibCore/ThreadEventQueue.cpp:108
#6  0x000000000066a7fd in Ladybird::EventLoopManagerQt::event_target_received_event ()
    at /scratch/wip/ladybird-git/work/serenity/Ladybird/Qt/EventLoopImplementationQt.cpp:154
#7  0x000000000066ae6c in Ladybird::EventLoopImplementationQtEventTarget::event ()
    at /scratch/wip/ladybird-git/work/serenity/Ladybird/Qt/EventLoopImplementationQtEventTarget.cpp:13
#8  0x00007817d0f9f958 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x7817c6cb7510, e=0x7817c6c6ccb0)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/widgets/kernel/qapplication.cpp:3287
#9  0x00007817d004262f in QCoreApplication::notifyInternal2 (receiver=0x7817c6cb7510, event=0x7817c6c6ccb0)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1134
#10 0x00007817d004294c in QCoreApplication::sendEvent (receiver=<optimized out>, event=<optimized out>)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1575
#11 0x00007817d004666c in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x7817c7ac83c0)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1932
#12 0x00007817d00469be in QCoreApplication::sendPostedEvents (receiver=<optimized out>, event_type=<optimized out>)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qcoreapplication.cpp:1789
#13 0x00007817d029a67f in postEventSourceDispatch (s=s@entry=0x7817c6ca50e0)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qeventdispatcher_glib.cpp:244
#14 0x00007817cbe9bb0d in g_main_dispatch (context=context@entry=0x7817c6d64180) at ../glib/gmain.c:3344
#15 0x00007817cbe9ef68 in g_main_context_dispatch_unlocked (context=0x7817c6d64180) at ../glib/gmain.c:4152
#16 g_main_context_iterate_unlocked (context=context@entry=0x7817c6d64180, block=block@entry=1, dispatch=dispatch@entry=1, self=<optimized out>) at ../glib/gmain.c:4217
#17 0x00007817cbe9f833 in g_main_context_iteration (context=0x7817c6d64180, may_block=may_block@entry=1) at ../glib/gmain.c:4282
#18 0x00007817d0299dfa in QEventDispatcherGlib::processEvents (this=0x7817c7a93e40, flags=...)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/kernel/qeventdispatcher_glib.cpp:394
#19 0x00007817d004de5a in QEventLoop::exec (this=this@entry=0x7f7fff25f6d0, flags=..., flags@entry=...)
    at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/global/qflags.h:34
#20 0x00007817d004bbe4 in QCoreApplication::exec () at /scratch/x11/qt6-qtbase/work/qtbase-everywhere-src-6.7.1/src/corelib/global/qflags.h:74
#21 0x00007817cd4dd79d in Core::EventLoop::exec () at /scratch/wip/ladybird-git/work/serenity/Userland/Libraries/LibCore/EventLoop.cpp:88
#22 0x00000000006893c0 in serenity_main () at /scratch/wip/ladybird-git/work/serenity/Ladybird/Qt/main.cpp:210
#23 0x000000000068ba48 in main () at /scratch/wip/ladybird-git/work/serenity/Userland/Libraries/LibMain/Main.cpp:43