Sentry

**Fixes**:

- Fix contexts from the scope not being attached to events correctly.
- Improve performance of event serialization.

**Features**:

- The Sentry SDK now has experimental support for performance monitoring.
The performance monitoring API allows manually creating transactions and instrumenting spans, and offers APIs for distributed tracing.
The API is currently disabled by default and needs to be enabled via a compile-time `SENTRY_PERFORMANCE_MONITORING` flag.
For more information, take a look at the more detailed [documentation of performance monitoring](https://docs.sentry.io/platforms/native/performance/).
- Sentry now has an explicit `sentry_flush` method that blocks the calling thread for the given time, waiting for the transport queue to be flushed. Custom transports need to implement a new `flush_hook` for this to work.

**Fixes**:

- Fix Sentry API deadlocking when the SDK was not initialized (or `sentry_init` failed).
- The rate limit handling of the default transports was updated to match the expected behavior.
- The Windows OS version is now read from the Registry and is more accurate.
- The `SENTRY_LIBRARY_TYPE` CMake option is now correctly honored.
- The Linux Modulefinder was once again improved to increase its memory safety and reliability.

**Thank you**:

Features, fixes and improvements in this release have been contributed by:

- [Mixaill](https://github.com/Mixaill)

**Features**:

- Add client-side stackwalking on Linux, Windows, and macOS (disabled by default).
- CMake: add ability to set solution folder name.
- Add AIX support.

**Fixes**:

- CMake: check whether libcurl was already found.
- Increment CXX standard version to 14 to allow crashpad to build.

**Internal**:

- Update Crashpad and Breakpad submodules to 2021-12-03.

**Thank you**:

Features, fixes and improvements in this release have been contributed by:

- [Mixaill](https://github.com/Mixaill)
- [ladislavmacoun](https://github.com/ladislavmacoun)
- [NattyNarwhal](https://github.com/NattyNarwhal)
- [mjvankampen](https://github.com/mjvankampen)

**Features**:

- Make the shutdown timeout configurable via `sentry_options_set_shutdown_timeout`.

**Fixes**:

- The crashpad backend compiles with mingw again.
- Build System improvements.

**Thank you**:

Features, fixes and improvements in this release have been contributed by:

- [irov](https://github.com/irov)
- [past-due](https://github.com/past-due)
- [andrei-mu](https://github.com/andrei-mu)
- [rpadaki](https://github.com/rpadaki)

**Fixes**:

- The crashpad backend now respects the `max_breadcrumbs` setting.
- Hanging HTTP requests will now be canceled on shutdown in the WinHTTP transport.
- The Modulefinder and Android unwinder now use safer memory access.
- Possible races and deadlocks have been fixed in `init`/`close`, and in API related to sessions.

**Thank you**:

Features, fixes and improvements in this release have been contributed by:

- [smibe](https://github.com/smibe)

**Fixes**:

- Fix a potential deadlock in macOS modulefinder.
- Lower Stack usage, to lower change of stack overflows.
- Avoid a double-free when parsing an invalid DSN.
- Improvements to Unity Builds and 32-bit Builds.
- Fix infinite recursion in signal handler by correctly cleaning up on shutdown.

**Internal**:

- Update Crashpad and Breakpad submodules to 2021-06-14.

**Thank you**:

Features, fixes and improvements in this release have been contributed by:

- [janisozaur](https://github.com/janisozaur)
- [bschatt](https://github.com/bschatt)
- [GenuineAster](https://github.com/GenuineAster)