QtWebEngine fails on macOS 10.14 if spellchecker disabled

I get the following build error when the spellchecker is disabled:

Undefined symbols for architecture x86_64:
"SpellCheckResult::SpellCheckResult(SpellCheckResult::Decoration, int, int, std::_1::vector<std::1::basic_string<unsigned short, base::string16_internals::string16_char_traits, std::_1::allocat
or<unsigned short> >, std::_1::allocator<std::1::basic_string<unsigned short, base::string16_internals::string16_char_traits, std::_1::allocator<unsigned short> > > > const&)", referenced from:
void std::__1::allocator<SpellCheckResult>::construct<SpellCheckResult>(SpellCheckResult*) in interfaces_jumbo_1.o
"SpellCheckResult::SpellCheckResult(SpellCheckResult const&)", referenced from:
void std::__1::allocator<SpellCheckResult>::construct<SpellCheckResult, SpellCheckResult&>(SpellCheckResult*, SpellCheckResult&&&) in interfaces_jumbo_1.o
"SpellCheckResult::~SpellCheckResult()", referenced from:
std::__1::allocator<SpellCheckResult>::destroy(SpellCheckResult*) in interfaces_jumbo_1.o
"mojo::EnumTraits<spellcheck::mojom::Decoration, SpellCheckResult::Decoration>::ToMojom(SpellCheckResult::Decoration)", referenced from:
mojo::internal::Serializer<spellcheck::mojom::Decoration, SpellCheckResult::Decoration>::Serialize(SpellCheckResult::Decoration, int*) in interfaces_jumbo_1.o
"mojo::EnumTraits<spellcheck::mojom::Decoration, SpellCheckResult::Decoration>::FromMojom(spellcheck::mojom::Decoration, SpellCheckResult::Decoration*)", referenced from:
mojo::internal::Serializer<spellcheck::mojom::Decoration, SpellCheckResult::Decoration>::Deserialize(int, SpellCheckResult::Decoration*) in interfaces_jumbo_1.o
"mojo::StructTraits<spellcheck::mojom::SpellCheckResultDataView, SpellCheckResult>::Read(spellcheck::mojom::SpellCheckResultDataView, SpellCheckResult*)", referenced from:
mojo::internal::Serializer<spellcheck::mojom::SpellCheckResultDataView, SpellCheckResult>::Deserialize(spellcheck::mojom::internal::SpellCheckResult_Data*, SpellCheckResult*, mojo::internal::SerializationContext*) in interfaces_jumbo_1.o
ld: symbol(s) not found for architecture x86_64