# 0.2.2 (January 14, 2022)

### Added

- Include a syslog identifier in log messages ([#1822])
- Added `Layer::with_syslog_identifier` method to override the syslog
  identifier ([#1822])

Thanks to @lunaryorn for contributing to this release!

[#1822]: #1822

The `time` crate bumped its MSRV to 1.53.0 in v0.3.6:
time-rs/time@2d37c01

Since `tracing-appender` has a non-optional dependency on `time`, it's
necessary to increase its MSRV to track this.

This branch adds initial support for using the [`valuable`] crate as an
opt-in `Value` type in `tracing`. `valuable` provides a mechanism for
defining custom ways to record user-implemented types, as well as
structured recording of standard library data structures such as maps,
arrays, and sets.

For more details, see the tracking issue #1570.

In `tracing` v0.2, the intent is for `valuable` to replace the existing
`tracing_core::field::Value` trait. However, in v0.1.x, `valuable`
support must be added in a backwards-compatible way, so recording types
that implement `valuable::Valueable` currently requires opting in using
a `field::valuable` wrapper function.

Since this is the first release of `valuable` and the API is still
stabilizing, we don't want to tie `tracing-core`'s stability to
`valuable`'s. Therefore, the valuable dependency is feature-flagged
*and* also requires `RUSTFLAGS="--cfg tracing_unstable"`.

[`valuable`]: https://github.com/tokio-rs/valuable

Co-authored-by: Daniel McKenna <daniel@emotech.co>
Co-authored-by: David Barsky <me@davidbarsky.com>
Co-authored-by: Eliza Weisman <eliza@buoyant.io>

## Motivation

In some cases, it can be useful to express a more complex filtering
behavior by composing multiple filters. This is especially useful when
re-using the same logic in multiple filters.


## Solution

This branch adds a new `FilterExt` extension trait with combinators for
composing filters. The current set of combinators are `And` (enables
spans/events that are enabled by *both* filters), `Or` (enables any span
or event enabled by *either* filter), and `Not` (negate the output of a
filter).

Signed-off-by: Eliza Weisman <eliza@buoyant.io>

Fixes https://rustsec.org/advisories/RUSTSEC-2022-0006.

## Motivation

`cargo audit` prevents us using `tracing-subscriber` at the moment.
Upgrading `thread_local` to 1.1.4 would fix that.

## Solution

Upgrade `thread_local`.

# 0.3.7 (Jan 25, 2022)

This release adds combinators for combining filters.

Additionally, this release also updates the `thread-local` crate to
v1.1.4, fixing warnings for the security advisory [RUSTSEC-2022-0006].
Note that previous versions of `tracing-subscriber` did not use any of
the `thread-local` crate's APIs effected by the vulnerability. However,
updating the version fixes warnings emitted by `cargo audit` and similar
tools.

### Added

- **filter**: Added combinators for combining filters ([#1578])

### Fixed

- **registry**: Updated `thread-local` to v1.1.4 ([#1858])

Thanks to new contributor @matze for contributing to this release!

[RUSTSEC-2022-0006]: https://rustsec.org/advisories/RUSTSEC-2022-0006
[#1578]: #1578
[#1858]: #1858