?? The tracer and profiling packages for PHP 7 and 8 are built on CentOS 7. These packages will not run on older GNU Linux versions like CentOS 6, Debian 7, and Ubuntu 12.04.

### Added
- Add single span ingestion mechanism #1628
- Add "recurse" => true option to hook/trace config array #1677

### Changed
- Allow Symfony EventDispatcher::dispatch hooks to recurse #1678

### Fixed
- Fix JIT compatibility under macOS #1661
- Fix -Werror=address-of-packed-member #1664
- Add support for ports on x-forwarded-for header #1675. Thanks, @estringana!

### Internal changes
- Move to CentOS 7; begin adding profiling deps #1660
- Add profiling sources #1606
- Build and package datadog-profiling in CI #1663
- Fix profiler config in randomized tests #1682

## Profiling (v0.8.0)

### Added
- Add `process_id` and `runtime_version` tags #1606.
- Add support for changing env vars per request, such as per-directory env var settings in Apache #1606.
- Add fake frame when truncating stacks #1679. This way users can tell when the stack is truncated.

### Changed
- Switch <php> to <?php #1680
- Raise max stack depth to 512 #1681
- Enable CPU Time profile by default #1663. This can disabled by setting the environment variable `DD_PROFILING_EXPERIMENTAL_CPU_TIME_ENABLED` to `0`, `off`, or `no`.
- Change logging format #1606. Add a new log level `trace`, which is even more verbose than `debug`.
- Stop sending a profile on every `phpinfo()` (or the equivalent command line option `--ri datadog-profiling`) #1606