tracing

Important

The Span::record_all method has been removed from the documented API. It was always unsuable via the documented API as it requried a ValueSet which has no publically documented constructors. The method remains, but should not be used outside of tracing macros.

Added

• attributes: Support constant expressions as instrument field names (#3158)
• Add record_all! macro for recording multiple values in one call (#3227)
• core: Improve code generation at trace points significantly (#3398)

Changed

• tracing-core: updated to 0.1.35 (#3414)
• tracing-attributes: updated to 0.1.31 (#3417)

Fixed

• Fix "name / parent" variant of event! (#2983)
• Remove 'r#' prefix from raw identifiers in field names (#3130)
• Fix perf regression when release_max_level_* not set (#3373)
• Use imported instead of fully qualified path (#3374)
• Make valueset macro sanitary (#3382)

Documented

• core: Add missing dyn keyword in Visit documentation code sample (#3387)

[ crates.io ] | [ docs.rs ]

This release updates the tracing-core dependency to v0.1.33 and the tracing-attributes dependency to v0.1.28.

Added

• core: Add index API for Field (#2820)
• core: Allow &[u8] to be recorded as event/span field (#2954)

Changed

• Bump MSRV to 1.63 (#2793)
• core: Use const thread_locals when possible (#2838)

Fixed

• Removed core imports in macros (#2762)
• attributes: Added missing RecordTypes for instrument (#2781)
• attributes: Change order of async and unsafe modifier (#2864)
• Fix missing field prefixes (#2878)
• attributes: Extract match scrutinee (#2880)
• Fix non-simple macro usage without message (#2879)
• Fix event macros with constant field names in the first position (#2883)
• Allow field path segments to be keywords (#2925)
• core: Fix missed register_callsite error (#2938)
• attributes: Support const values for target and name (#2941)
• Prefix macro calls with ::core to avoid clashing with local macros (#3024)

This release fixes a potential stack use-after-free in the Instrument::into_inner method. Only uses of this method are affected by this bug.

Fixed

• Use mem::ManuallyDrop instead of mem::forget in Instrument::into_inner (#2765)

Thanks to @cramertj and @manishearth for finding and fixing this issue!

This release adds several additional features to the tracing macros. In addition, it updates the tracing-core dependency to v0.1.32 and the tracing-attributes dependency to v0.1.27.

Added

• Allow constant field names in macros (#2617)
• Allow setting event names in macros (#2699)
• core: Allow ValueSets of any length (#2508)

Changed

• tracing-attributes: updated to 0.1.27
• tracing-core: updated to 0.1.32
• attributes: Bump minimum version of proc-macro2 to 1.0.60 (#2732)
• attributes: Generate less dead code for async block return type hint (#2709)

Fixed

• Use fully qualified names in macros for items exported from std prelude (#2621, #2757)
• attributes: Allow [clippy::let_with_type_underscore] in macro-generated code ([#2609])
• attributes: Allow unknown_lints in macro-generated code (#2626)
• attributes: Fix a compilation error in #[instrument] when the "log" feature is enabled (#2599)

Documented

• Add axum-insights to relevant crates. (#2713)
• Fix link to RAI pattern crate documentation ([#2612])
• Fix docs typos and warnings (#2581)
• Add clippy-tracing to related crates (#2628)
• Add tracing-cloudwatch to related crates (#2667)
• Fix deadlink to tracing-etw repo (#2602)

This tracing release changes the Drop implementation for Instrumented Futures so that the attached Span is entered when dropping the Future. This means that events emitted by the Future's Drop implementation will now be recorded within its Span. It also adds #[inline] hints to methods called in the event! macro's expansion, for an improvement in both binary size and performance.

Additionally, this release updates the tracing-attributes dependency to v0.1.24, which updates the syn dependency to v2.x.x. tracing-attributes v0.1.24 also includes improvements to the #[instrument] macro; see the tracing-attributes 0.1.24 release notes for details.

Added

• Instrumented futures will now enter the attached Span in their Drop implementation, allowing events emitted when dropping the future to occur within the span ([#2562])
• #[inline] attributes for methods called by the event! macros, making generated code smaller (#2555)
• attributes: level argument to #[instrument(err)] and #[instrument(ret)] to override the level of the generated return value event (#2335)
• attributes: Improved compiler error message when #[instrument] is added to a const fn (#2418)

Changed

• tracing-attributes: updated to 0.1.24
• Removed unneeded cfg-if dependency (#2553)
• attributes: Updated syn dependency to 2.0 (#2516)

Fixed

• attributes: Fix clippy::unreachable warnings in #[instrument]-generated code (#2356)
• attributes: Removed unused "visit" feature flag from syn dependency (#2530)

Documented

• attributes: Documented default level for #[instrument(err)] (#2433)
• attributes: Improved documentation for levels in #[instrument] (#2350)

Thanks to @nitnelave, @jsgf, @Abhicodes-crypto, @LukeMathWalker, @andrewpollack, @quad, @klensy, @davidpdrsn, @dbidwell94, @ldm0, @NobodyXu, @ilsv, and @daxpedda for contributing to this release!

This release of tracing incorporates changes from tracing-core v0.1.30 and tracing-attributes v0.1.23, including the new Subscriber::on_register_dispatch method for performing late initialization after a Subscriber is registered as a Dispatch, and bugfixes for the #[instrument] attribute. Additionally, it fixes instances of the bare_trait_objects lint, which is now a warning on tracing's MSRV and will become an error in the next edition.

Fixed

• attributes: Incorrect handling of inner attributes in #[instrument]ed functions (#2307)
• attributes: Incorrect location of compiler diagnostic spans generated for type errors in #[instrument]ed async fns (#2270)
• attributes: Updated syn dependency to fix compilation with -Z minimal-versions (#2246)
• bare_trait_objects warning in valueset! macro expansion (#2308)

Added

• core: Subscriber::on_register_dispatch method (#2269)
• core: WeakDispatch type and Dispatch::downgrade() function (#2293)

Changed

• tracing-core: updated to 0.1.30
• tracing-attributes: updated to 0.1.23

Documented

• Added tracing-web and reqwest-tracing to related crates (#2283, #2331)

Thanks to new contributors @compiler-errors, @e-nomem, @WorldSEnder, @Xiami2012, and @tl-rodrigo-gryzinski, as well as @jswrenn and @CAD97, for contributing to this release!

• Fix record_all panic (#3432)

This release reduces the overhead of callsite registration by using new tracing-core APIs.

Added

• Use DefaultCallsite to reduce callsite registration overhead ([#2083])

Changed

• tracing-core: updated to 0.1.27

This release includes bug fixes for the "log" support feature and for the use of both scoped and global default dispatchers in the same program.

Fixed

• Failure to use the global default dispatcher when a thread sets a local default dispatcher before the global default is set (#2065)
• log: Compilation errors due to async block/fn futures becoming !Send when the "log" feature flag is enabled (#2073)
• Broken links in documentation (#2068)

Thanks to @ben0x539 for contributing to this release!

This release adds new span_enabled! and event_enabled! variants of the enabled! macro, for testing whether a subscriber would specifically enable a span or an event.

Added

• span_enabled! and event_enabled! macros (#1900)
• Several documentation improvements (#2010, #2012)

Fixed

• Compilation warning when compiling for <=32-bit targets (including wasm32) (#2060)

Thanks to @guswynn, @arifd, @hrxi, @CAD97, and @name1e5s for contributing to this release!

This release reduces the overhead of creating and dropping disabled spans significantly, which should improve performance when no tracing subscriber is in use or when spans are disabled by a filter.

Fixed

• attributes: Compilation failure with --minimal-versions due to a too-permissive syn dependency (#1960)

Changed

• Reduced Drop overhead for disabled spans (#1974)
• tracing-attributes: updated to 0.1.20

This release increases the minimum supported Rust version (MSRV) to 1.49.0. In addition, it fixes some relatively rare macro bugs.

Added

• Added tracing-forest to the list of related crates (#1935)

Changed

• Updated minimum supported Rust version (MSRV) to 1.49.0 (#1913)

Fixed

• Fixed the warn! macro incorrectly generating an event with the TRACE level (#1930)
• Fixed macro hygiene issues when used in a crate that defines its own concat! macro, for real this time (#1918)

Thanks to @QnnOkabayashi, @nicolaasg, and @teohhanhui for contributing to this release!

This release adds experimental support for recording structured field values using the valuable crate. See this blog post for details on valuable.

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

This release also adds a new enabled! macro for testing if a span or event would be enabled.

Added

• field: Experimental support for recording field values using the valuable crate (#1608, #1888, #1887)
• enabled! macro for testing if a span or event is enabled (#1882)

Changed

• tracing-core: updated to 0.1.22
• tracing-attributes: updated to 0.1.19

Fixed

• log: Fixed "use of moved value" compiler error when the "log" feature is enabled (#1823)
• Fixed macro hygiene issues when used in a crate that defines its own concat! macro (#1842)
• A very large number of documentation fixes and improvements.

Thanks to @@Vlad-Scherbina, @Skepfyr, @Swatinem, @guswynn, @teohhanhui, @xd009642, @tobz, @d-e-s-o@0b01, and @nickelc for contributing to this release!

This release adds support for recording Option<T> where T: Value as typed tracing field values. It also includes significant performance improvements for functions annotated with the #[instrument] attribute when the generated span is disabled.

Changed

• tracing-core: updated to v0.1.21
• tracing-attributes: updated to v0.1.18

Added

• field: Value impl for Option<T> where T: Value (#1585)
• attributes: - improved performance when skipping #[instrument]-generated spans below the max level (#1600, #1605, #1614, #1616, #1617)

Fixed

• instrument: added missing Future implementation for WithSubscriber, making the WithDispatch extension trait actually useable (#1602)
• Documentation fixes and improvements (#1595, #1601, #1597)

Thanks to @brianburgers, @mattiast, @DCjanus, @oli-obk, and @matklad for contributing to this release!

This release fixes an issue where the RustDoc documentation was rendered incorrectly. It doesn't include any actual code changes, and is very boring and can be ignored.

Fixed

• docs: Incorrect documentation rendering due to unclosed <div> tag (#1572)

This release adds a new Span::or_current method to aid in efficiently propagating span contexts to spawned threads or tasks. Additionally, it updates the tracing-core version to 0.1.20 and the tracing-attributes version to 0.1.16, ensuring that a number of new features in those crates are present.

Fixed

• instrument: Added missing WithSubscriber implementations for futures and other types (#1424)

Added

• Span::or_current method, to help with efficient span context propagation (#1538)
• attributes: add skip_all option to #[instrument] (#1548)
• attributes: record primitive types as primitive values rather than as fmt::Debug (#1378)
• core: NoSubscriber, a no-op Subscriber implementation ([#1549])
• core: Added Visit::record_f64 and support for recording floating-point values (#1507, #1522)
• A large number of documentation improvements and fixes (#1369, #1398, #1435, #1442, #1524, #1556)

Thanks to new contributors @dzvon and @mbergkvist, as well as @teozkr, @maxburke, @LukeMathWalker, and @jsgf, for contributing to this release!

Fixed

• attributes: Compatibility between #[instrument] and async-trait v0.1.43 and newer ([#1228])
• Several documentation fixes (#1305, #1344)

Added

• Subscriber impl for Box<dyn Subscriber + Send + Sync + 'static> (#1358)
• Subscriber impl for Arc<dyn Subscriber + Send + Sync + 'static> (#1374)
• Symmetric From impls for existing Into impls on span::Current, Span, and Option<Id> (#1335, #1338)
• From<EnteredSpan> implementation for Option<Id>, allowing EnteredSpan to be used in a span! macro's parent: field (#1325)
• Attributes::fields accessor that returns the set of fields defined on a span's Attributes (#1331)

Thanks to @Folyd, @nightmared, and new contributors @rmsc and @Fishrock123 for contributing to this release!

Added

• Span::entered method for entering a span and moving it into a guard by value rather than borrowing it (#1252)

Thanks to @matklad for contributing to this release!

Fixed

• attributes: Compiler error when using #[instrument(err)] on functions which return impl Trait (#1236)
• Fixed broken match arms in event macros (#1239)
• Documentation improvements (#1232)

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

Fixed

• attributes: Compiler error when using #[instrument(err)] on functions with mutable parameters (#1167)
• attributes: Missing function visibility modifier when using #[instrument] with async-trait (#977)
• attributes Removed unused syn features ([#928])
• log: Fixed an issue where the tracing macros would generate code for events whose levels are disabled statically by the log crate's static_max_level_XXX features (#1175)
• Fixed deprecations and clippy lints (#1195)
• Several documentation fixes and improvements (#941, #965, #981, #1146, #1215)

Changed

• attributes: tracing-futures dependency is no longer required when using #[instrument] on async functions (#808)
• attributes: Updated tracing-attributes minimum dependency to v0.1.12 (#1222)

Thanks to @nagisa, @Txuritan, @TaKO8Ki, @okready, and @krojew for contributing to this release!

Changed

• Updated pin-project-lite dependency to 0.2 (#1108)

Fixed

• Incorrect inlining of Span::new, Span::new_root, and Span::new_child_of, which could result in dispatcher::get_default being inlined at the callsite (#994)
• Regression where using a struct field as a span or event field when other fields on that struct are borrowed mutably would fail to compile (#987)

Changed

• Updated tracing-core to 0.1.17 (#992)

Added

• Instrument trait and Instrumented type for attaching a Span to a Future (#808)
• Copy implementations for Level and LevelFilter (#992)
• Multiple documentation fixes and improvements (#964, #980, #981)

Thanks to @nagisa, and new contributors @SecurityInsanity, @froydnj, @jyn514 and @TaKO8Ki for contributing to this release!

Changed

• Significantly reduced assembly generated by macro invocations (#943)
• Updated tracing-core to 0.1.15 (#943)

Added

• Documented minimum supported Rust version policy (#941)

Fixed

• Updated tracing-core to fix incorrect calculation of the global max level filter (#908)

Added

• attributes: Support for using self in field expressions when instrumenting async-trait functions (#875)
• Several documentation improvements (#832, #881, #896, #897, #911, #913)

Thanks to @anton-dutov, @nightmared, @mystor, and @toshokan for contributing to this release!

Fixed

• Fixed a bug where LevelFilter::OFF (and thus also the static_max_level_off feature flag) would enable all traces, rather than none (#853)
• log: Fixed tracing macros and Spans not checking log::max_level before emitting log records (#870)

Changed

• macros: Macros now check the global max level (LevelFilter::current) before the per-callsite cache when determining if a span or event is enabled. This significantly improves performance in some use cases (#853)
• macros: Simplified the code generated by macro expansion significantly, which may improve compile times and/or rustc optimizatation of surrounding code (#869, #869)
• macros: Macros now check the static max level before checking any runtime filtering, improving performance when a span or event is disabled by a static_max_level_XXX feature flag (#868)
• LevelFilter is now a re-export of the tracing_core::LevelFilter type, it can now be used interchangeably with the versions in tracing-core and tracing-subscriber (#853)
• Significant performance improvements when comparing LevelFilters and Levels (#853)
• Updated the minimum tracing-core dependency to 0.1.12 (#853)

Added

• macros: Quoted string literals may now be used as field names, to allow fields whose names are not valid Rust identifiers (#790)
• docs: Several documentation improvements (#850, #857, #841)
• LevelFilter::current() function, which returns the highest level that any subscriber will enable (#853)
• Subscriber::max_level_hint optional trait method, for setting the value returned by LevelFilter::current() (#853)

Thanks to new contributors @cuviper, @ethanboxx, @ben0x539, @dignati, @colelawrence, and @rbtcollins for helping out with this release!

Changed

• log: Moved verbose span enter/exit log records to "tracing::span::active" target, allowing them to be filtered separately (#833)
• log: All span lifecycle log records without fields now have the Trace log filter, to guard against log users enabling them by default with blanket level filtering (#833)

Fixed

• log/macros: Fixed missing implicit imports of the tracing::field::debug and tracing::field::display functions inside the macros when the "log" feature is enabled (#835)

Added

• attributes: Support for arbitrary expressions as fields in #[instrument] (#672)
• attributes: #[instrument] now emits a compiler warning when ignoring unrecognized input (#672, #786)
• Improved documentation on using tracing in async code (#769)

Changed

• Updated tracing-core dependency to 0.1.11

Fixed

• macros: Excessive monomorphization in macros, which could lead to longer compilation times (#787)
• log: Compiler warnings in macros when log or log-always features are enabled (#753)
• Compiler error when tracing-core/std feature is enabled but tracing/std is not (#760)

Thanks to @nagisa for contributing to this release!

Changed

• macros: Replaced use of legacy local_inner_macros with $crate:: (#740)

Added

• Docs fixes and improvements (#742, #731, #730)

Thanks to @bnjjj, @blaenk, and @LukeMathWalker for contributing to this release!

Added

• log: When using the log compatibility feature alongside a tracing Subscriber, log records for spans now include span IDs (#613)
• attributes: Support for using #[instrument] on methods that are part of async-trait trait implementations (#711)
• attributes: Optional #[instrument(err)] argument to automatically emit an event if an instrumented function returns Err (#637)
• Added #[must_use] attribute to the guard returned by subscriber::set_default (#685)

Changed

• log: Made log records emitted by spans much less noisy when span IDs are not available (#613)

Fixed

• Several typos in the documentation (#656, #710, #715)

Thanks to @FintanH, @shepmaster, @inanna-malick, @zekisharif, @bkchr, @majecty, @ilana and @nightmared for contributing to this release!

Added

• field: field::Empty type for declaring empty fields whose values will be recorded later (#548)
• field: field::Value implementations for Wrapping and NonZero* numbers (#538)
• attributes: Support for adding arbitrary literal fields to spans generated by #[instrument] (#569)
• attributes: #[instrument] now emits a helpful compiler error when attempting to skip a function parameter (#600)

Changed

• attributes: The #[instrument] attribute was placed under an on-by-default feature flag "attributes" (#603)

Fixed

• Broken and unresolvable links in RustDoc (#595)

Thanks to @oli-cosmian and @Kobzol for contributing to this release!

Added

• Span::with_subscriber method to access the subscriber that tracks a Span (#503)
• API documentation now shows which features are required by feature-flagged items (#523)
• Improved README examples (#496)
• Documentation links to related crates (#507)

Added

• Span::is_none method (#475)
• LevelFilter::into_level method (#470)
• LevelFilter::from_level function and From<Level> impl (#471)
• Documented minimum supported Rust version (#482)

Fixed

• Incorrect parameter type to Span::follows_from that made it impossible to call (#467)
• Missing whitespace in log records generated when enabling the log feature flag (#484)
• Typos and missing links in documentation (#405, #423, #439)

Added

• Support for destructuring in arguments to #[instrument]ed functions (#397)
• Generated field for self parameters when #[instrument]ing methods (#397)
• Optional skip argument to #[instrument] for excluding function parameters from generated spans (#359)
• Added dispatcher::set_default and subscriber::set_default APIs, which return a drop guard (#388)

Fixed

• Some minor documentation errors (#356, #370)

Fixed

• Fixed #[instrument]ed async functions not compiling on nightly-2019-09-11 or newer (#342)

Changed

• Significantly reduced performance impact of skipped spans and events when a Subscriber is not in use (#326)
• The log feature will now only cause tracing spans and events to emit log records when a Subscriber is not in use (#346)

Added

• Added support for overriding the name of the span generated by #[instrument] (#330)
• log-always feature flag to emit log records even when a Subscriber is set (#346)

Changed

• Reorganized and improved API documentation (#317)

Removed

• Dev-dependencies on ansi_term and humantime crates, which were used only for examples (#316)

Changed

• New (curly-brace free) event message syntax to place the message in the first field rather than the last (#309)

Fixed

• Fixed a regression causing macro stack exhaustion when the log feature flag is enabled (#304)

Added

• std::error::Error as a new primitive type (#277)
• Support for mixing key-value fields and format_args messages without curly braces as delimiters (#288)

Changed

• tracing-core dependency to 0.1.5 (#294)
• tracing-attributes dependency to 0.1.2 (#297)

Added

• Support for no-std + liballoc (#263)

Changed

• Using the #[instrument] attribute on async fns no longer requires a feature flag (#258)

Fixed

• The #[instrument] macro now works on generic functions (#262)

Added

• #[instrument] attribute for automatically adding spans to functions (#253)

Added

• Log messages when a subscriber indicates that a span has closed, when the log feature flag is enabled (#180).

Changed

• tracing-core minimum dependency version to 0.1.2 (#174).

Fixed

• Fixed an issue where event macro invocations with a single field, using local variable shorthand, would recur infinitely (#166).
• Fixed uses of deprecated tracing-core APIs (#174).

Added

• Span::none() constructor, which does not require metadata and returns a completely empty span (#147).
• Span::current() function, returning the current span if it is known to the subscriber (#148).

Fixed

• Broken macro imports when used prefixed with tracing:: (#152).

Changed

• cfg_if dependency to 0.1.9.

Fixed

• Compilation errors when the log feature is enabled (#131).
• Unclear wording and typos in documentation (#124, #128, #142).

• Initial release