https://chromium-review.googlesource.com/c/chromium/src/+/1096057

https://bugs.chromium.org/p/chromium/issues/detail?id=851604 tries doing this, and a bunch of tests pretty stubbornly fail with it set.

The only consistently failing suite is browser_tests. Usually only one shard fails, but it then has stacks all over the place (and the output takes a while to load because of that): https://chromium-swarm.appspot.com/task?id=3e122996e3ce5110&refresh=10&show_raw=1



Received signal 11 SEGV_MAPERR 000000000008
0   browser_tests                       0x0000000106d0f89c base::debug::StackTrace::StackTrace(unsigned long) + 28
1   browser_tests                       0x0000000106d0f6c1 base::debug::(anonymous namespace)::StackDumpSignalHandler(int, __siginfo*, void*) + 2401
2   libsystem_platform.dylib            0x00007fff65213f5a _sigtramp + 26
3   libsystem_malloc.dylib              0x00007fff650af342 tiny_malloc_from_free_list + 431
4   browser_tests                       0x0000000106d2cfe8 base::PowerMonitorDeviceSource::PlatformInit() + 200
5   browser_tests                       0x0000000106c7e0f0 base::PowerMonitorDeviceSource::PowerMonitorDeviceSource() + 32
6   browser_tests                       0x000000010490d104 content::BrowserMainLoop::PostMainMessageLoopStart() + 196
7   browser_tests                       0x0000000104912aa0 content::BrowserMainRunnerImpl::Initialize(content::MainFunctionParams const&, std::__1::unique_ptr<content::BrowserProcessSubThread, std::__1::default_delete<content::BrowserProcessSubThread> >) + 1088
8   browser_tests                       0x000000010490c005 content::BrowserMain(content::MainFunctionParams const&, std::__1::unique_ptr<content::BrowserProcessSubThread, std::__1::default_delete<content::BrowserProcessSubThread> >) + 229
9   browser_tests                       0x0000000106a9e843 content::RunBrowserProcessMain(content::MainFunctionParams const&, content::ContentMainDelegate*, std::__1::unique_ptr<content::BrowserProcessSubThread, std::__1::default_delete<content::BrowserProcessSubThread> >) + 195
10  browser_tests                       0x0000000106a9f94e content::ContentMainRunnerImpl::Run() + 686
11  browser_tests                       0x00000001093c9167 service_manager::Main(service_manager::MainParams const&) + 2855
12  browser_tests                       0x0000000106a9e754 content::ContentMain(content::ContentMainParams const&) + 68
13  browser_tests                       0x00000001074dc88c content::BrowserTestBase::SetUp() + 3212
14  browser_tests                       0x0000000106d65f10 InProcessBrowserTest::SetUp() + 800
15  browser_tests                       0x00000001036e365d testing::Test::Run() + 109
16  browser_tests                       0x00000001036e4370 testing::TestInfo::Run() + 320
17  browser_tests                       0x00000001036e49a7 testing::TestCase::Run() + 279
18  browser_tests                       0x00000001036f1137 testing::internal::UnitTestImpl::RunAllTests() + 871
19  browser_tests                       0x00000001036f0dad testing::UnitTest::Run() + 109
20  browser_tests                       0x0000000106d8a1b6 base::TestSuite::Run() + 166
21  browser_tests                       0x0000000106bff0f5 ChromeTestSuiteRunner::RunTestSuite(int, char**) + 37
22  browser_tests                       0x0000000107515816 content::LaunchTests(content::TestLauncherDelegate*, unsigned long, int, char**) + 470
23  browser_tests                       0x0000000106bff60b LaunchChromeTests(unsigned long, content::TestLauncherDelegate*, int, char**) + 347
24  browser_tests                       0x0000000106bff04e main + 94
25  libdyld.dylib                       0x00007fff64f05015 start + 1
[end of stack trace]

[678/912] AllForms/FormStructureBrowserTest.DataDrivenHeuristics/59 (CRASHED)



[0613/064345.066630:FATAL:child_port_handshake.cc(111)] Check failed: server_port.is_valid(). 
0   crashpad_handler                    0x000000010277d3ac base::debug::StackTrace::StackTrace(unsigned long) + 28
1   crashpad_handler                    0x00000001026c501f logging::LogMessage::~LogMessage() + 223
2   crashpad_handler                    0x000000010279c9c5 crashpad::ChildPortHandshake::RunServerForFD(base::ScopedGeneric<int, base::internal::ScopedFDCloseTraits>, crashpad::ChildPortHandshake::PortRightType) + 597
3   crashpad_handler                    0x0000000102691ee6 crashpad::HandlerMain(int, char**, std::__1::vector<std::__1::unique_ptr<crashpad::UserStreamDataSource, std::__1::default_delete<crashpad::UserStreamDataSource> >, std::__1::allocator<std::__1::unique_ptr<crashpad::UserStreamDataSource, std::__1::default_delete<crashpad::UserStreamDataSource> > > > const*) + 4790
4   libdyld.dylib                       0x00007fff64f05015 start + 1
5   ???                                 0x0000000000000008 0x0 + 8



These are probably the two most common stacks.

I probably won't have time to debug this.