Logrus v1.10.0

This release focuses on substantial performance improvements, concurrency correctness, and better interoperability with modern Go logging APIs.

🚀 Performance

Major improvements across TextFormatter, entry handling, and common logger paths:

• ~17% lower geomean runtime across the benchmark suite
• ~27% higher geomean formatter throughput
• Common enabled logging paths are ~30–44% faster
• WithError is ~40% faster
• Chained fields are ~46% faster
• TextFormatter paths are up to ~40% faster
• Allocation counts are reduced by ~25–74% across measured TextFormatter cases, with the largest reductions in colored output

The improvements also show up in complete logger paths:

• Logger + TextFormatter is ~31% faster, with ~24% fewer allocations
• Logger + JSONFormatter is ~21% faster, with ~10% fewer allocations

JSONFormatter itself remains largely unchanged in runtime performance, with small allocation reductions.

🔄 log/slog interoperability

v1.10 adds bidirectional interoperability between Logrus and Go's log/slog:

• A Logrus slog hook can forward existing Logrus entries to an slog logger.
• hooks/slog.NewHandler implements slog.Handler, allowing log/slog records to use an existing Logrus logger and its hooks, formatter, and output.
• The handler preserves levels, fields, groups, context, record timestamps, and optionally caller information.
• Caller reporting is configured per handler, without requiring Logrus's logger-wide ReportCaller option.
• Custom slog levels can be mapped to Logrus levels.
• The hook and handler can be combined, providing a practical path for incrementally migrating from Logrus to log/slog without requiring an all-at-once transition.

This allows applications to migrate their logging API and logging backend independently: existing Logrus call sites can start using an slog backend, while new slog code can continue using an established Logrus setup.

🔒 Concurrency & Correctness

• Fix reentrant logging deadlocks, including logging from within MarshalJSON or formatter code.
• Fix generic Log, Logf, Logln, and LogFn methods unexpectedly panicking when called with PanicLevel, contrary to their documented behavior.
• Eliminate race conditions in entry and formatter paths.
• Improve locking boundaries around formatters and hooks.

➕ Added

• TextFormatter now automatically enables colors on Windows terminals with ANSI support, matching behavior on other platforms.
• Entry.Caller can now be set explicitly and is preserved across derived entries. When caller reporting is enabled, Logrus only detects and populates caller information when none was provided, allowing custom caller detection and wrapper-aware logging without adding additional caller configuration APIs.
• Add minimal, composable logging interfaces for each log level, allowing consumers to depend on narrower interfaces and making logging implementations easier to substitute or adapt.
• Expand CI verification to include TinyGo and every cross-compile target reported by go tool dist list, improving coverage across alternative toolchains and platforms.

⚠️ Behavioral Changes

• Minimum supported Go version is now 1.23.
• TextFormatter now renders []byte as raw/quoted strings instead of numeric slices. If you relied on the previous slice-of-ints output, convert explicitly before logging.
• TextFormatter now uses dim cyan for debug output and dim white for trace output in colorized TTY output.
• Entry.HasCaller is now deprecated in favor of checking Entry.Caller directly. A //go:fix inline directive was added so existing uses can be updated automatically.
• MutexWrap, which was unintentionally exposed as public API, is deprecated. It remains available as an alias for compatibility but should not be used directly.

v1.10 is primarily a performance, correctness, and interoperability release with no intentional breaking public API changes.

Full Changelog: https://github.com/sirupsen/logrus/compare/v1.9.4...v1.10.0