tracing-subscriber

Fixed

• Change registry exit to decrement local span ref only (#3331)
• Make Layered propagate on_register_dispatch (#3379)

Changed

• tracing: updated to 0.1.42 (#3418)

Performance

• Remove clone_span on enter (#3289)

Documented

• Fix a few small things in the format module (#3339)
• Fix extra closing brace in layer docs (#3350)
• Fix link in FmtSpan docs (#3411)

[ crates.io ] | [ docs.rs ]

Fixed

• Escape ANSI escape sequences in logs (#3368)

Added

• Implement Clone for EnvFilter (#3360)

[ crates.io ] | [ docs.rs ]

This release updates the tracing dependency to v0.1.41 and the tracing-serde dependency to v0.2.0.

Added

• Add set_span_events to fmt::Subscriber (#2962)
• tracing: Allow &[u8] to be recorded as event/span field (#2954)

Changed

• Set log max level when reloading (#1270)
• Bump MSRV to 1.63 (#2793)
• Use const thread_locals when possible (#2838)
• Don't gate with_ansi() on the "ansi" feature (#3020)
• Updated tracing-serde to 0.2.0 (#3160)

This release of tracing-subscriber adds support for the NO_COLOR environment variable (an informal standard to disable emitting ANSI color escape codes) in fmt::Layer, reintroduces support for the chrono crate, and increases the minimum supported Rust version (MSRV) to Rust 1.63.0.

It also introduces several minor API improvements.

Added

• chrono: Add chrono implementations of FormatTime (#2690)
• subscriber: Add support for the NO_COLOR environment variable in fmt::Layer (#2647)
• fmt: make format::Writer::new() public (#2680)
• filter: Implement layer::Filter for Option<Filter> (#2407)

Changed

• log: bump version of tracing-log to 0.2 (#2772)
• Increased minimum supported Rust version (MSRV) to 1.63.0+.

Thanks to @shayne-fletcher, @dmlary, @kaifastromai, and @jsgf for contributing!

This release of tracing-subscriber fixes a build error when using env-filter with recent versions of the regex crate. It also introduces several minor API improvements.

Fixed

• env-filter: Add "unicode-case" and "unicode-perl" to the regex dependency, fixing a build error with recent versions of regex (#2566)
• A number of minor documentation typos and other fixes (#2384, #2378, #2368, #2548)

Added

• filter: Add fmt::Display impl for filter::Targets (#2343)
• fmt: Made with_ansi(false) no longer require the "ansi" feature, so that ANSI formatting escapes can be disabled without requiring ANSI-specific dependencies (#2532)

Changed

• fmt: Dim targets in the Compact formatter, matching the default formatter (#2409)

Thanks to @keepsimple1, @andrewhalle, @LeoniePhiline, @LukeMathWalker, @howardjohn, @daxpedda, and @dbidwell94 for contributing to this release!

This release of tracing-subscriber fixes a regression introduced in v0.3.15 where Option::None's Layer implementation would set the max level hint to OFF. In addition, it adds several new APIs, including the Filter::event_enabled method for filtering events based on fields values, and the ability to log internal errors that occur when writing a log line.

This release also replaces the dependency on the unmaintained [ansi-term] crate with the [nu-ansi-term] crate, resolving an informational security advisory (RUSTSEC-2021-0139) for [ansi-term]'s maintainance status. This increases the minimum supported Rust version (MSRV) to Rust 1.50+, although the crate should still compile for the previous MSRV of Rust 1.49+ when the ansi feature is not enabled.

Fixed

• layer: Option::None's Layer impl always setting the max_level_hint to LevelFilter::OFF (#2321)
• Compilation with -Z minimal versions (#2246)
• env-filter: Clarify that disabled level warnings are emitted by tracing-subscriber (#2285)

Added

• fmt: Log internal errors to stderr if writing a log line fails (#2102)
• fmt: FmtLayer::log_internal_errors and FmtSubscriber::log_internal_errors methods for configuring whether internal writer errors are printed to stderr (#2102)
• fmt: #[must_use] attributes on builders to warn if a Subscriber is configured but not set as the default subscriber (#2239)
• filter: Filter::event_enabled method for filtering an event based on its fields (#2245, #2251)
• filter: Targets::default_level accessor ([#2242])

Changed

• ansi: Replaced dependency on unmaintained ansi-term crate with nu-ansi-term ((#2287, fixes informational advisory RUSTSEC-2021-0139)
• tracing-core: updated to 0.1.30
• Minimum Supported Rust Version (MSRV) increased to Rust 1.50+ (when the ansi) feature flag is enabled (#2287)

Documented

• fmt: Correct inaccuracies in fmt::init documentation (#2224)
• filter: Fix incorrect doc link in filter::Not combinator (#2249)

Thanks to new contributors @cgbur, @DesmondWillowbrook, @RalfJung, and @poliorcetics, as well as returning contributors @CAD97, @connec, @jswrenn, @guswynn, and @bryangarza, for contributing to this release!

This release fixes a bug where the reload layer would fail to pass through max_level_hint to the underlying layer, potentially breaking filtering.

Fixed

• reload: pass through max_level_hint to the inner Layer (#2204)

Thanks to @guswynn for contributing to this release!

This release fixes multiple filtering bugs in the Layer implementations for Option<impl Layer> and Vec<impl Layer>.

Fixed

• layer: Layer::event_enabled implementation for Option<impl Layer<S>> returning false when the Option is None, disabling all events globally (#2193)
• layer: Layer::max_level_hint implementation for Option<impl Layer<S>> incorrectly disabling max level filtering when the option is None (#2195)
• layer: Layer::max_level_hint implementation for Vec<impl Layer<S>> returning LevelFilter::ERROR rather than LevelFilter::OFF when the Vec is empty (#2195)

Thanks to @CAD97 and @guswynn for contributing to this release!

This release of tracing-subscriber fixes a compilation failure due to an incorrect tracing-core dependency that was introduced in v0.3.12.

Changed

• tracing_core: Updated minimum dependency version to 0.1.28 (#2190)

This release of tracing-subscriber adds a new Layer::event_enabled method, which allows Layers to filter events after their field values are recorded; a Filter implementation for reload::Layer, to make using reload with per-layer filtering more ergonomic, and additional inherent method downcasting APIs for the Layered type. In addition, it includes dependency updates, and minor fixes for documentation and feature flagging.

Added

• layer: Layer::event_enabled method, which can be implemented to filter events based on their field values (#2008)
• reload: Filter implementation for reload::Layer (#2159)
• layer: Layered::downcast_ref and Layered::is inherent methods (#2160)

Changed

• parking_lot: Updated dependency on parking_lot to 0.13.0 (#2143)
• Replaced lazy_static dependency with once_cell ([#2147])

Fixed

• Don't enable tracing-core features by default (#2107)
• Several documentation link and typo fixes (#2064, #2068, #[2077], #2161, #1088)

Thanks to @ben0x539, @jamesmunns, @georgemp, @james7132, @jswrenn, @CAD97, and @guswynn for contributing to this release!

This is a bugfix release for the Filter implementation for EnvFilter added in v0.3.10.

Fixed

• env-filter: Added missing Filter::on_record callback to EnvFilter's Filter impl (#2058)
• env-filter: Fixed method resolution issues when calling EnvFilter methods with both the Filter and Layer traits in scope (#2057)
• env-filter: Fixed EnvFilter::builder().parse() and other parsing methods returning an error when parsing an empty string (#2052)

Thanks to new contributor @Ma124 for contributing to this release!

This release adds several new features, including a Filter implementation and new builder API for EnvFilter, support for using a Vec<L> where L: Layer as a Layer, and a number of smaller API improvements to make working with dynamic and reloadable layers easier.

Added

• registry: Implement Filter for EnvFilter, allowing it to be used with per-layer filtering (#1983)
• registry: Filter::on_new_span, Filter::on_enter, Filter::on_exit, Filter::on_close and Filter::on_record callbacks to allow Filters to track span states internally (#1973, #2017, #2031)
• registry: Filtered::filter and Filtered::filter_mut accessors (#1959)
• registry: Filtered::inner and Filtered::inner_mut accessors to borrow the wrapped Layer (#2034)
• layer: Implement Layer for Vec<L: Layer>, to allow composing together a dynamically sized list of Layers (#2027)
• layer: Layer::boxed method to make type-erasing Layers easier (#2026)
• fmt: fmt::Layer::writer and fmt::Layer::writer_mut accessors (#2034)
• fmt: fmt::Layer::set_ansi method to allow changing the ANSI formatting configuration at runtime (#2034)
• env-filter: EnvFilter::builder to configure a new EnvFilter prior to parsing it (#2035)
• Several documentation fixes and improvements (#1972, #1971, #2023, #2023)

Fixed

• fmt: fmt::Layer's auto traits no longer depend on the Subscriber type parameter's auto traits (#2025)
• env-filter: Fixed missing help text when the ansi feature is disabled (#2029)

Thanks to new contributors @TimoFreiberg and @wagenet, as well as @CAD97 for contributing to this release!

This release updates the minimum supported Rust version (MSRV) to 1.49.0, and updates the (optional) dependency on parking_lot to v0.12.

Changed

• Updated minimum supported Rust version (MSRV) to 1.49.0 (#1913)
• parking_lot: updated to v0.12 (008339d)

Added

• fmt: Documentation improvements (#1926, #1927)

This release adds experimental support for recording structured field values using the valuable crate to the format::Json formatter. In particular, user-defined types which are recorded using their valuable::Valuable implementations will be serialized as JSON objects, rather than using their fmt::Debug representation. See this blog post for details on valuable.

Note that valuable support currently requires --cfg tracing_unstable. See the documentation for details.

Additionally, this release includes a number of other smaller API improvements.

Added

• json: Experimental support for recording valuable values as structured JSON (#1862, #1901)
• filter: Targets::would_enable method for testing if a Targets filter would enable a given target (#1903)
• fmt: map_event_format, map_fmt_fields, and map_writer methods to fmt::Layer and fmt::SubscriberBuilder (#1871)

Changed

• tracing-core: updated to 0.1.22

Fixed

• Set smallvec minimal version to 1.2.0, to fix compilation errors with -Z minimal-versions (#1890)
• Minor documentation fixes (#1902, #1893)

Thanks to @guswynn, @glts, and @lilyball for contributing to this release!

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!

This release adds configuration options to tracing_subscriber::fmt to log source code locations for events.

Added

• fmt: Added with_file and with_line_number configuration methods to fmt::Format, fmt::SubscriberBuilder, and fmt::Layer (#1773)

Fixed

• fmt: Removed incorrect leading comma from span fields with the Pretty formatter (#1833)

Deprecated

• fmt: Deprecated Pretty::with_source_location, as it can now be replaced by the more general Format, SubscriberBuilder, and Layer methods (#1773)

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

This release re-enables RUST_LOG filtering in tracing_subscriber::fmt's default initialization methods, and adds an OffsetLocalTime formatter for using local timestamps with the time crate.

Added

• fmt: Added OffsetLocalTime formatter to fmt::time for formatting local timestamps with a fixed offset (#1772)

Fixed

• fmt: Added a Targets filter to fmt::init() and fmt::try_init() when the "env-filter" feature is disabled, so that RUST_LOG is still honored (#1781)

Thanks to @marienz and @ishitatsuyuki for contributing to this release!

This release contains bugfixes for the fmt module, as well as documentation improvements.

Fixed

• fmt: Fixed fmt not emitting log lines when timestamp formatting fails (#1689)
• fmt: Fixed double space before thread IDs with Pretty formatter (#1778)
• Several documentation improvements (#1608, #1699, #1701)

Thanks to new contributors @Swatinem and @rukai for contributing to this release!

This release fixes a pair of regressions in tracing-subscriber's fmt module.

Fixed

• fmt: Fixed missing event fields with Compact formatter (#1755)
• fmt: Fixed PrettyFields formatter (and thus format::Pretty event formatter) ignoring the fmt::Layer's ANSI color code configuration (#1747)

Added

• Use argv0 for syslog identifier (#3372)

This release fixes a few issues related to feature flagging.

Fixed

• time: Compilation error when enabling the "time" feature flag without also enabling the "local-time" feature flag (#1685)
• registry: Unused method warnings when the "std" feature is enabled but the "registry" feature is disabled (#1686)

This is a breaking release of tracing-subscriber. The primary breaking change in this release is the removal of the dependency on the chrono crate, due to RUSTSEC-2020-0159. To replace chrono, support is added for formatting timestamps using the time crate instead.

In addition, this release includes a number of other breaking API changes, such as adding (limited) support for #![no_std] targets, removing previously deprecated APIs, and more.

Breaking Changes

• Removed APIs deprecated in the v0.2.x release series.
• Renamed Layer::new_span to Layer::on_new_span (#1674)
• Removed Layer impl for Arc<L: Layer<S>> and Arc<dyn Layer<S> + ...> (#1649)
• Replaced the chrono crate with the time crate for timestamp formatting, to resolve RUSTSEC-2020-0159 (#1646)
• Removed json and env-filter from default features. They must now be enabled explictly (#1647). This means that RUST_LOG-based filters will not work unless the env-filter feature is enabled.
• Changed FormatEvent::format_event and FormatFields::format_fields trait methods to take a Writer type, rather than a &mut dyn fmt::Write trait object (#1661)
• Changed the signature of the MakeWriter trait by adding a lifetime parameter (#781)

Changed

• layer: Renamed Layer::new_span to Layer::on_new_span (#1674)
• fmt: Changed FormatEvent::format_event and FormatFields::format_fields trait methods to take a Writer type, rather than a &mut dyn fmt::Write trait object (#1661)
• json, env-filter: json and env-filter feature flags are no longer enabled by default (#1647)

Removed

• Removed deprecated CurrentSpan type (#1320)
• registry: Removed deprecated SpanRef::parents iterator, replaced by SpanRef::scope in #1431 ([#1648)])
• layer: Removed deprecated Context::scope iterator, replaced by Context::span_scope and Context::event_scope in #1431 and #1434 ([#1648)])
• layer: Removed Layer impl for Arc<L: Layer<S>> and Arc<dyn Layer<S> + ...>. These interfere with per-layer filtering. (#1649)
• fmt: Removed deprecated LayerBuilder type (#1673)
• fmt: Removed fmt::Layer::on_event (renamed to fmt::Layer::fmt_event) (#1673)
• fmt, chrono: Removed the chrono feature flag and APIs for using the chrono crate for timestamp formatting (#1646)

Added

• fmt, time: LocalTime and UtcTime types for formatting timestamps using the time crate (#1646)
• fmt: Added a lifetime parameter to the MakeWriter trait, allowing it to return a borrowed writer. This enables implementations of MakeWriter for types such as Mutex<T: io::Write> and std::fs::File. (#781)
• env-filter: Documentation improvements ([#1637])
• Support for some APIs on #![no_std] targets, by disabling the std feature flag (#1660)

Thanks to @Folyd and @nmathewson for contributing to this release!

This release fixes an issue where a Layer implementation's custom downcast_raw implementation was lost when wrapping that layer with a per-layer filter.

Fixed

• registry: Forward Filtered::downcast_raw to wrapped Layer (#1619)

Added

• Documentation improvements (#1596, #1601)

Thanks to @bryanburgers for contributing to this release!

This release contains a number of bug fixes, including a fix for tracing-subscriber failing to compile on the minimum supported Rust version of 1.42.0. It also adds IntoIterator implementations for the Targets type.

Fixed

• Fixed compilation on Rust 1.42.0 (#1580, #1581)
• registry: Ensure per-layer filter enabled state is cleared when a global filter short-circuits filter evaluation (#1575)
• layer: Fixed Layer::on_layer not being called for Boxed Layers, which broke per-layer filtering (#1576)

Added

• filter: Added Targets::iter, returning an iterator over the set of target-level pairs enabled by a Targets filter (#1574)
• filter: Added IntoIterator implementations for Targets and &Targets (#1574)

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

This release fixes a few bugs in the per-layer filtering API added in v0.2.21.

Fixed

• env-filter: Fixed excessive EnvFilter memory use (#1568)
• filter: Fixed a panic that may occur in debug mode when using per-layer filters together with global filters (#1569)
• Fixed incorrect documentation formatting (#1572)

This fixes a regression where the filter::ParseError type was accidentally renamed.

Fixed

• filter: Fix filter::ParseError accidentally being renamed to filter::DirectiveParseError (#1558)

This release introduces the Filter trait, a new API for per-layer filtering. This allows controlling which spans and events are recorded by various layers individually, rather than globally.

In addition, it adds a new Targets filter, which provides a lighter-weight version of the filtering provided by EnvFilter, as well as other smaller API improvements and fixes.

Deprecated

• registry: SpanRef::parent_id, which cannot properly support per-layer filtering. Use .parent().map(SpanRef::id) instead. (#1523)

Fixed

• layer Context methods that are provided when the Subscriber implements LookupSpan no longer require the "registry" feature flag (#1525)
• layer fmt::Debug implementation for Layered no longer requires the S type parameter to implement Debug (#1528)

Added

• registry: Filter trait, Filtered type, Layer::with_filter method, and other APIs for per-layer filtering (#1523)
• filter: FilterFn and DynFilterFn types that implement global (Layer) and per-layer (Filter) filtering for closures and function pointers (#1523)
• filter: Targets filter, which implements a lighter-weight form of EnvFilter-like filtering (#1550)
• env-filter: Added support for filtering on floating-point values (#1507)
• layer: Layer::on_layer callback, called when layering the Layer onto a Subscriber (#1523)
• layer: Layer implementations for Box<L> and Arc<L> where L: Layer ([#1536])
• layer: Layer implementations for Box<dyn Layer<S> + Send + Sync + 'static> and Arc<dyn Layer<S> + Send + Sync + 'static> ([#1536])
• A number of small documentation fixes and improvements (#1553, #1544, #1539, #1524)

Special thanks to new contributors @jsgf and @maxburke for contributing to this release!

Fixed

• fmt: Fixed fmt printing only the first source for errors with a chain of sources (#1460)
• fmt: Fixed missing space between level and event in the Pretty formatter (#1498)
• json: Fixed Json formatter not honoring without_time and with_level configurations (#1463)

Added

• registry: Improved panic message when cloning a span whose ID doesn't exist, to aid in debugging issues with multiple subscribers (#1483)
• registry: Improved documentation on span ID generation (#1453)

Thanks to new contributors @joshtriplett and @lerouxrgd, and returning contributor @teozkr, for contributing to this release!

Deprecated

• registry: SpanRef::parents, SpanRef::from_root, and Context::scope iterators, which are replaced by new SpanRef::scope and Scope::from_root iterators (#1413)

Added

• registry: SpanRef::scope method, which returns a leaf-to-root Iterator including the leaf span (#1413)
• registry: Scope::from_root method, which reverses the scope iterator to iterate root-to-leaf (#1413)
• registry: Context::event_span method, which looks up the parent span of an event (#1434)
• registry: Context::event_scope method, returning a Scope iterator over the span scope of an event (#1434)
• fmt: MakeWriter::make_writer_for method, which allows returning a different writer based on a span or event's metadata (#1141)
• fmt: MakeWriterExt trait, with with_max_level, with_min_level, with_filter, and, and or_else combinators (#1274)
• fmt: MakeWriter implementation for Arc<W> where &W: io::Write (#1274)

Thanks to @teozkr and @Folyd for contributing to this release!

Deprecated

• Deprecated the CurrentSpan type, which is inefficient and largely superseded by the registry API (#1321)

Fixed

• json: Invalid JSON emitted for events in spans with no fields (#1333)
• json: Missing span data for synthesized new span, exit, and close events (#1334)
• fmt: Extra space before log lines when timestamps are disabled (#1355)

Added

• env-filter: Support for filters on spans whose names contain any characters other than { and ] (#1368)

Thanks to @Folyd, and new contributors @akinnane and @aym-v for contributing to this release!

Fixed

• fmt: Pretty formatter now honors with_ansi(false) to disable ANSI terminal formatting (#1240)
• fmt: Fixed extra padding when using Pretty formatter (#1275)
• chrono: Removed extra trailing space with ChronoLocal time formatter (#1103)

Added

• fmt: Added FmtContext::current_span() method, returning the current span (#1290)
• fmt: FmtSpan variants may now be combined using the | operator for more granular control over what span events are generated (#1277)

Thanks to new contributors @cratelyn, @dignati, and @zicklag, as well as @Folyd, @matklad, and @najamelan, for contributing to this release!

Fixed

• env-filter: Fixed directives where the level is in mixed case (such as Info) failing to parse (#1126)
• fmt: Fixed fmt::Subscriber not providing a max-level hint (#1251)
• tracing-subscriber no longer enables tracing and tracing-core's default features (#1144)

Changed

• chrono: Updated chrono dependency to 0.4.16 (#1189)
• log: Updated tracing-log dependency to 0.1.2

Thanks to @salewski, @taiki-e, @davidpdrsn and @markdingram for contributing to this release!

Fixed

• fmt: Fixed wrong lifetime parameters on FormatFields impl for FmtContext (#1082)

Added

• fmt: format::Pretty, an aesthetically pleasing, human-readable event formatter for local development and user-facing CLIs (#1080)
• fmt: FmtContext::field_format, which returns the subscriber's field formatter (#1082)

Fixed

• registry: Fixed Registry::new allocating an excessively large amount of memory, most of which would never be used (#1064)

Changed

• registry: Improved new_span performance by reusing HashMap allocations for Extensions (#1064)
• registry: Significantly improved the performance of Registry::enter and Registry::exit (#1058)

Changed

• Updated tracing-core to 0.1.17 (#992)

Added

• env-filter: Added support for filtering on targets which contain dashes (#1014)
• env-filter: Added a warning when creating an EnvFilter that contains directives that would enable a level disabled by the tracing crate's static_max_level features (#1021)

Thanks to @jyn514 and @bkchr for contributing to this release!

Fixed

• env-filter: Fixed a regression where Option<Level> lost its Into<LevelFilter> impl (#966)
• env-filter: Fixed EnvFilter enabling spans that should not be enabled when multiple subscribers are in use (#927)

Changed

• json: format::Json now outputs fields in a more readable order (#892)
• Updated tracing-core dependency to 0.1.16

Added

• fmt: Add BoxMakeWriter for erasing the type of a MakeWriter implementation (#958)
• fmt: Add TestWriter MakeWriter implementation to support libtest output capturing (#938)
• layer: Add Layer impl for Option<T> where T: Layer (#910)
• env-filter: Add From<Level> impl for Directive (#918)
• Multiple documentation fixes and improvements

Thanks to @Pothulapati, @samrg472, @bryanburgers, @keetonian, and @SriRamanujam for contributing to this release!

Fixed

• env-filter: Incorrect max level hint when filters involving span field values are in use (#907)
• registry: Fixed inconsistent span stacks when multiple registries are in use on the same thread (#901)

Changed

• env-filter: regex dependency enables fewer unused feature flags (#899)

Thanks to @bdonlan and @jeromegn for contributing to this release!

Fixed

• docs: Incorrect formatting (#862)

Changed

• filter: LevelFilter is now a re-export of the tracing_core::LevelFilter type, it can now be used interchangeably with the versions in tracing and tracing-core (#853)
• filter: Significant performance improvements when comparing LevelFilters and Levels (#853)
• Updated the minimum tracing-core dependency to 0.1.12 (#853)

Added

• filter: LevelFilter and EnvFilter now participate in tracing-core's max level hinting, improving performance significantly in some use cases where levels are disabled globally (#853)

Fixed

• fmt: Fixed compilation failure on MSRV when the chrono feature is disabled (#844)

Added

• fmt: Span lookup methods defined by layer::Context are now also provided by FmtContext (#834)

Changed

• fmt: When the chrono dependency is enabled, the SystemTime timestamp formatter now emits human-readable timestamps rather than using SystemTime's fmt::Debugimplementation (chrono is still required for customized timestamp formatting) (#807)
• ansi: Updated ansi_term dependency to 0.12 (#816)

Added

• json: with_span_list method to configure the JSON formatter to include a list of all spans in the current trace in formatting events (similarly to the text formatter) (#741)
• json: with_current_span method to configure the JSON formatter to include a field for the current span (the leaf of the trace) in formatted events (#741)
• fmt: with_thread_names and with_thread_ids methods to configure fmt::Subscribers and fmt::Layers to include the thread name and/or thread ID of the current thread when formatting events (#818)

Thanks to new contributors @mockersf, @keetonian, and @Pothulapati for contributing to this release!

Changed

• parking_lot: Updated the optional parking_lot dependency to accept the latest parking_lot version (#774)

Fixed

• fmt: Fixed events with explicitly overridden parent spans being formatted as though they were children of the current span (#767)

Added

• fmt: Added the option to print synthesized events when spans are created, entered, exited, and closed, including span durations (#761)
• Documentation clarification and improvement (#762, #769)

Thanks to @rkuhn, @greenwoodcm, and @Ralith for contributing to this release!

Fixed

• fmt: Fixed an issue in the JSON formatter where using Span::record would result in malformed spans (#709)

Added

• Add latest symlink builder option (#3447)

Fixed

• Fix RollingFileAppender broken links in docs (#3445)
• Fix parsing of date from filename when no time is incuded (#3471)

This release includes several API ergonomics improvements, including shorthand constructors for many types, and an extension trait for initializing subscribers using method-chaining style. Additionally, several bugs in less commonly used fmt APIs were fixed.

Added

• fmt: Shorthand free functions for constructing most types in fmt (including tracing_subscriber::fmt() to return a SubscriberBuilder, tracing_subscriber::fmt::layer() to return a format Layer, etc) (#660)
• registry: Shorthand free function tracing_subscriber::registry() to construct a new registry (#660)
• Added SubscriberInitExt extension trait for more ergonomic subscriber initialization (#660)

Changed

• fmt: Moved LayerBuilder methods to Layer (#655)

Deprecated

• fmt: LayerBuilder, as Layer now implements all builder methods (#655)

Fixed

• fmt: Fixed Compact formatter not omitting levels with with_level(false) (#657)
• fmt: Fixed fmt::Layer duplicating the fields for a new span if another layer has already formatted its fields (#634)
• fmt: Added missing space when using record to add new fields to a span that already has fields (#659)
• Updated outdated documentation (#647)

Fixed

• env-filter: Regression where filter directives were selected in the order they were listed, rather than most specific first (#624)

Added

• fmt: Added flatten_event to SubscriberBuilder (#599)
• fmt: Added with_level to SubscriberBuilder (#594)

Changed

• filter: EnvFilter directive selection now behaves correctly (i.e. like env_logger) (#583)

Fixed

• filter: Fixed EnvFilter incorrectly allowing less-specific filter directives to enable events that are disabled by more-specific filters (#583)
• filter: Multiple significant EnvFilter performance improvements, especially when filtering events generated by log records (#578, #583)
• filter: Replaced BTreeMap with Vec in DirectiveSet, improving iteration performance significantly with typical numbers of filter directives (#580)

A big thank-you to @samschlegel for lots of help with EnvFilter performance tuning in this release!

Breaking Changes

• fmt: Renamed Context to FmtContext (#420, #425)
• fmt: Renamed Builder to SubscriberBuilder (#420)
• filter: Removed Filter. Use EnvFilter instead (#434)

Added

• registry: Registry, a Subscriber implementation that Layers can use as a high-performance, in-memory span store. (#420, #425, #432, #433, #435)
• registry: Added LookupSpan trait, implemented by Subscribers to expose stored span data to Layers (#420)
• fmt: Added fmt::Layer, to allow composing log formatting with other Layers
• fmt: Added support for JSON field and event formatting (#377, #415)
• filter: Documentation for filtering directives (#554)

Changed

• fmt: Renamed Context to FmtContext (#420, #425) (BREAKING)
• fmt: Renamed Builder to SubscriberBuilder (#420) (BREAKING)
• fmt: Reimplemented fmt::Subscriber in terms of the Registry and Layers (#420)

Removed

• filter: Removed Filter. Use EnvFilter instead (#434) (BREAKING)

Fixed

• fmt: Fixed memory leaks in the slab used to store per-span data (3c35048)
• fmt: fmt::SubscriberBuilder::init not setting up log compatibility (#489)
• fmt: Spans closed by a child span closing not also closing their parents (#514)
• Layer: Fixed Layered subscribers failing to downcast to their own type (#549)
• Layer: Fixed Layer::downcast_ref returning invalid references (#454)

Fixed

• fmt: Fixed empty {} printed after spans with no fields (f079f2d)
• fmt: Fixed inconsistent formatting when ANSI colors are disabled (506a482)
• fmt: Fixed misaligned levels when ANSI colors are disabled (eba1adb)
• Fixed warnings on nightly Rust compilers (#558)

Added

• env_filter: Documentation for filtering directives (#554)
• registry, env_filter: Updated smallvec dependency to 0.1 (#543)

Fixed

• registry: Fixed a memory leak in the slab used to store per-span data (3c35048)
• Layer: Fixed Layered subscribers failing to downcast to their own type (#549)
• fmt: Fixed a panic when multiple layers insert FormattedFields extensions from the same formatter type (1c3bb70)
• fmt: Fixed fmt::Layer::on_record inserting a new FormattedFields when formatted fields for a span already exist (1c3bb70)

Fixed

• registry: Removed inadvertently committed dbg! macros (#533)

Added

• fmt: Public FormattedFields::new constructor (#478)
• fmt: Added examples to fmt::Layer documentation (#510)
• Documentation now shows what feature flags are required by each API item (#525)

Fixed

• fmt: Missing space between timestamp and level (#480)
• fmt: Incorrect formatting with with_target(false) (#481)
• fmt: fmt::SubscriberBuilder::init not setting up log compatibility (#489)
• registry: Spans exited out of order not being closed properly on exit (#509)
• registry: Memory leak when spans are closed by a child span closing (#514)
• registry: Spans closed by a child span closing not also closing their parents (#514)
• Compilation errors with no-default-features (#499, #500)

Added

• LookupSpans implementation for Layered (#448)
• SpanRef::from_root to iterate over a span's parents from the root (#460)
• Context::scope, to iterate over the current context from the root (#460)
• Context::lookup_current, which returns a SpanRef to the current span's data (#460)

Changed

• Lifetimes on some new Context methods to be less restrictive (#460)

Fixed

• Layer::downcast_ref returning invalid references (#454)
• Compilation failure on 32-bit platforms (#462)
• Compilation failure with ANSI formatters (#438)

Added

• Registry, a reusable span store that Layers can use a high-performance, in-memory store. (#420, #425, #432, #433, #435)
• Reimplemented fmt::Subscriber in terms of the Registry and Layers (#420)
• Add benchmarks for fmt subscriber (#421)
• Add support for JSON field and event formatting (#377, #415)

Changed

• BREAKING: Change fmt::format::FormatFields and fmt::format::FormatEvent to accept a mandatory FmtContext. These FormatFields and FormatEvent will likely see additional breaking changes in subsequent alpha. (#420, #425)
• BREAKING: Removed Filter. Use EnvFilter instead (#434)

Contributors

Thanks to all the contributors to this release!

• @pimeys for #377 and #415

Added

• Add init and try_init functions to FmtSubscriber (#385)
• Add ChronoUtc and ChronoLocal timers, RFC 3339 support (#387)
• Add tracing::subscriber::set_default which sets the default subscriber and returns a drop guard. This drop guard will reset the dispatch on drop (#388).

Fixed

• Fix default level for EnvFilter. Setting RUST_LOG=target previously only the ERROR level, while it should enable everything. tracing-subscriber now defaults to TRACE if no level is specified (#401)
• Fix tracing-log feature flag for init + try_init. The feature flag tracing_log was used instead of the correct tracing-log. As a result, both tracing-log and tracing_log needed to be specified in order to initialize the global logger. Only tracing-log needs to be specified now (#400).

Contributors

Thanks to all the contributors to this release!

• @emschwartz for #385, #387, #400 and #401
• @bIgBV for #388

Fixed

• Spans not being closed properly when FmtSubscriber::current_span is used (#371)

Fixed

• Spans entered twice on the same thread sometimes being completely exited when the more deeply-nested entry is exited (#361)
• Setting with_ansi(false) on FmtSubscriber not disabling ANSI color formatting for timestamps (#354)
• Incorrect reference counting in FmtSubscriber that could cause spans to not be closed when all references are dropped (#366)

Fixed

• Layered subscribers not properly forwarding calls to current_span (#350)