sentry-native: Alternative backends on Windows don't catch crashes caused by `abort()`

Using Breakpad or inproc on Windows results in most crashes not being captured.

When does the problem happen

• During build
• During run-time
• When capturing a hard crash

Environment

• OS: Only Windows (in my case, Windows 10, 64-bit in VirtualBox)
• Compiler: MSVC 19
• CMake version and config: 3.21.2 -D SENTRY_BACKEND=breakpad -D BUILD_SHARED_LIBS=OFF

Steps To Reproduce

Just a simple boilerplate setup does it. Using abort() to cause the crash.

int main() {
  std::cout << "hello world" << std::endl;

  sentry_options_t* options = sentry_options_new();
  sentry_options_set_dsn(options, 'dsn redacted');
  sentry_options_set_debug(options, 1);

  sentry_init(options);

  std::this_thread::sleep_for(std::chrono::milliseconds(2000));

  abort();

  sentry_close();
}

Log output

This is the logs when it doesn’t work. As you can see, no crash is captured.

hello world
[sentry] INFO using database path "C:\Users\vagrant\NonRepos\SentryNativeTutorial\.sentry-native"
[sentry] DEBUG starting transport
[sentry] DEBUG starting background worker thread
[sentry] DEBUG starting backend
[sentry] DEBUG background worker thread started
The terminal process "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -Command ./install/bin/tutorial.exe" terminated with exit code: 1.

However, if I swap out abort(); for

  volatile char* invalid_memory = nullptr;
  *invalid_memory = '\0';  // crash

to invoke a different kind of crash, I get

hello world
[sentry] INFO using database path "C:\Users\vagrant\NonRepos\SentryNativeTutorial\.sentry-native"
[sentry] DEBUG starting transport
[sentry] DEBUG starting background worker thread
[sentry] DEBUG starting backend
[sentry] DEBUG background worker thread started
[sentry] INFO entering breakpad minidump callback
[sentry] DEBUG merging scope into event
[sentry] DEBUG adding attachments to envelope
[sentry] DEBUG sending envelope
[sentry] DEBUG serializing envelope into buffer
[sentry] INFO crash has been captured
The terminal process "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -Command ./install/bin/tutorial.exe" terminated with exit code: 1.

That is the first run, and on subsequent runs I see the envelope is uploaded and appears in the Sentry UI.

Similarly, if I change over to use crashpad as the backend, things work fine (but crashpad is not an option for me on this project). Things also work fine on Linux and Mac with the breakpad backend.

In my project, there’s a lot of assertions so most crashes are caused in the way that Windows can’t handle them.

For now, my hacky workaround is to register my own signal handler like so:

[[noreturn]] void windows_signal_handler(int signal) {
  volatile char* invalid_memory = nullptr;
  *invalid_memory = '\0';  // raising SEH exception EXCEPTION_ACCESS_VIOLATION_WRITE
  // unreachable
}

std::signal(SIGABRT, windows_signal_handler);

This results in the full stack trace appearing on the UI, albeit with an extra frame or two.