In Ubuntu, we compile arm builds natively (not cross-compiled) on hosts that have an arm64 kernel. Since https://chromium.googlesource.com/v8/v8.git/+/0c168a90ffc34e3e4defee0c1cc39fe522dae2c0, v8 fails to compile because mksnapshot crashes during the build with the following stack trace:

Thread 1 "mksnapshot" received signal SIGBUS, Bus error.
std::__fill_a<v8::internal::compiler::InstructionOperand*, v8::internal::compiler::InstructionOperand> () at /usr/include/c++/6/bits/stl_algobase.h:685
685 *__first = __value;
(gdb) bt
#0 std::__fill_a<v8::internal::compiler::InstructionOperand*, v8::internal::compiler::InstructionOperand> () at /usr/include/c++/6/bits/stl_algobase.h:685
#1 std::fill<v8::internal::compiler::InstructionOperand*, v8::internal::compiler::InstructionOperand> () at /usr/include/c++/6/bits/stl_algobase.h:731
#2 v8::internal::compiler::InstructionSelector::EmitTableSwitch () at ../../v8/src/compiler/instruction-selector.cc:1511
#3 0xab054c98 in v8::internal::compiler::InstructionSelector::VisitSwitch () at ../../v8/src/compiler/arm/instruction-selector-arm.cc:2042
#4 0xaac234e4 in v8::internal::compiler::InstructionSelector::VisitControl () at ../../v8/src/compiler/instruction-selector.cc:917
#5 0xaac235d0 in v8::internal::compiler::InstructionSelector::VisitBlock () at ../../v8/src/compiler/instruction-selector.cc:822
#6 0xaac237d6 in v8::internal::compiler::InstructionSelector::SelectInstructions () at ../../v8/src/compiler/instruction-selector.cc:69
#7 0xaac771b0 in v8::internal::compiler::InstructionSelectionPhase::Run () at ../../v8/src/compiler/pipeline.cc:1253
#8 v8::internal::compiler::PipelineImpl::Run<v8::internal::compiler::InstructionSelectionPhase, v8::internal::compiler::Linkage*> () at ../../v8/src/compiler/pipeline.cc:706
#9 0xaac7942c in v8::internal::compiler::PipelineImpl::ScheduleAndSelectInstructions () at ../../v8/src/compiler/pipeline.cc:1804
#10 0xaac7a3da in v8::internal::compiler::PipelineImpl::ScheduleAndGenerateCode () at ../../v8/src/compiler/pipeline.cc:1905
#11 v8::internal::compiler::Pipeline::GenerateCodeForCodeStub () at ../../v8/src/compiler/pipeline.cc:1692
#12 0xaabf7620 in v8::internal::compiler::CodeAssembler::GenerateCode () at ../../v8/src/compiler/code-assembler.cc:76
#13 0xaaba1bc6 in BuildWithCodeStubAssemblerCS () at ../../v8/src/builtins/builtins.cc:110
#14 0xaaba51a0 in v8::internal::Builtins::SetUp () at ../../v8/src/builtins/builtins.cc:153
#15 0xaae2086e in v8::internal::Isolate::Init () at ../../v8/src/isolate.cc:2533
#16 0xaaafd2bc in v8::SnapshotCreator::SnapshotCreator () at ../../v8/src/api.cc:484
#17 0xaab05be2 in v8::V8::CreateSnapshotDataBlob () at ../../v8/src/api.cc:593
#18 0xaaaf4c84 in main () at ../../v8/src/snapshot/mksnapshot.cc:164

The issue appears to be that despite this code here - https://chromium.googlesource.com/v8/v8.git/+/d094fa76f3dd0bb5fc3f4c669762aa97d88e0f76/src/zone/zone.cc#70, there are some cases where Zone::NewArray can return a pointer that is not 8-byte aligned even if the requested size is divisible by 8. Specifically, if the call requires a new segment to be allocated, then the returned pointer may not by 8-byte aligned.