v3.9.0
=== Improvements ===
* **Added experimental opt-in support for thread safe assertions**
  * Read the documentation for full details
* **The default test run order has been changed to random**
* Passing assertions are significantly faster when the reporter does not ask for `assertionEnded` events on passing assertions.
  * This is the default behaviour of e.g. Console or Compact reporter
  * Simple `REQUIRE(true)` is 60% faster in Release and 80% faster in Debug build configuration
  * Simple `REQUIRE_NOTHROW` is 230% faster in Release and 430% faster in Debug build configuration
  * Simple `REQUIRE_THROWS` is ~3% faster in Release and 20% faster in Debug build configuration (throwing introduces enough overhead that the optimizations inside Catch2 are mostly irrelevant)
* Small (2-5%) improvement if the reporter asks for `assertionEnded` events for passing assertions.
* The exit code constants are part of the Session API. (#2955, #2976)
* Suppressed unsigned integer overflow checking in locations with intended overflow (#2965)
* Reporters flush output after writing metadata, e.g. rng seed (#2964)
* Added unreachable after `FAIL` and `SKIP` macros (#2941)
  * This allows the compiler to understand that the execution does not continue past the macro, and avoids warnings.
* Added fast path for `assertionStarting` event when no reporter requires it
  * For backwards compatibility, this fast path is opt-in
  * A reporter can opt in by changing its `ReporterPreferences::shouldReportAllAssertionStarts`
* Improved last seen source location tracking to be more precise
  * This is used when reporting unexpected exceptions from tests
=== Fixes ===
* Fixed formatting of tags with more than 100 tests in the default `--list-tags` output (#2963)
* Fixed Clang-Tidy's `readability-static-accessed-through-instance` in tests
* Fixed most of Clang-Tidy's `cppcoreguidelines-avoid-non-const-global-variables` (#2582)
* The lifetime of scoped messages now strictly obeys their scope (#1759, #2019, #2959)
  * Previously Catch2 would try to keep them around during unexpected exception, to provide helpful context.
  * The amount of surprises the irregularities caused was not worth the occasional utility provided.
* `TEMPLATE_TEST_CASE_SIG` can handle signatures consisting of only types (#2680, #2995)
* Moved `catch_test_run_info.hpp` up from `internal/` subfolder into the main one (#2972)
=== Miscellaneous ===
* pkg-config files are now generated at install time (#2979)
  * This fixes missing debug suffix in library names
  * This fixes install prefix mismatch between build config and actuall installation

v3.8.1
=== Fixes ===
* Fixed bug where catch_discover_tests fails when no TEST_CASEs are present (#2962)
* Fixed Clang 19 -Wc++20-extensions warning (#2968)

v3.8.0
=== Improvements ===
* Added `std::initializer_list` overloads for `(Unordered)RangeEquals` matcher (#2915, #2919)
* Added explicit casts to silence GCC's `Wconversion` (#2875)
* Made the use of `builtin_constant_p` tricks in assertion macros configurable (#2925)
  * It is used to prod GCC-like compilers into providing warnings for the asserted expressions, but the compilers miscompile it annoyingly often.
* Cleaned out Clang-Tidy's `performance-enum-size` warnings
* Added support for using `from_range` generator with iterators with `value_type = const T` (#2926)
  * This is not correct `value_type` typedef, but it is used in the wild and the change does not make the code meaningfully worse.
=== Fixes ===
* Fixed crash when stringifying pre-1970 (epoch) dates on Windows (#2944)
=== Miscellaneous ===
* Fixes and improvements for `catch_discover_tests` CMake helper
  * Removed redundant `CTEST_FILE` param when creating the indirection file for `PRE_TEST` discovery mode (#2936)
  * Rewrote the test discovery logic to use output from the JSON reporter
    * This means that `catch_discover_tests` now requires CMake 3.19 or newer
  * Added `ADD_TAGS_AS_LABELS` option. If specified, each CTest test will be labeled with corrensponding Catch2's test tag
* Bumped up the minimum required CMake version to build Catch2 to 3.16
* Meson build now provides option to avoid installing Catch2
* Bazel build is moved to Bzlmod.

v3.7.1
=== Improvements ===
* Applied the JUnit reporter's optimization from last release to the SonarQube reporter
* Suppressed `-Wuseless-cast` in `CHECK_THROWS_MATCHES` (#2904)
* Standardize exit codes for various failures
  * Running no tests is now guaranteed to exit with 2 (without the `--allow-running-no-tests` flag)
  * All tests skipped is now always 4 (...)
  * Assertion failures are now always 42
  * and so on
=== Fixes ===
* Fixed out-of-bounds access when the arg parser encounters single `-` as an argument (#2905)
=== Miscellaneous ===
* Added `catch_config_prefix_messages.hpp` to meson build (#2903)
* `catch_discover_tests` now supports skipped tests (#2873)
  * You can get the old behaviour by calling `catch_discover_tests` with `SKIP_IS_FAILURE` option.

v3.7.0
=== Improvements ===
* Slightly improved compile times of benchmarks
* Made the resolution estimation in benchmarks slightly more precise
* Added new test case macro, `TEST_CASE_PERSISTENT_FIXTURE` (#2885, #1602)
  * Unlike `TEST_CASE_METHOD`, the same underlying instance is used for all partial runs of that test case
* **MASSIVELY** improved performance of the JUnit reporter when handling successful assertions (#2897)
  * For 1 test case and 10M assertions, the new reporter runs 3x faster and uses up only 8 MB of memory, while the old one needs 7 GB of memory.
* Reworked how output redirects works.
  * Combining a reporter writing to stdout with capturing reporter no longer leads to the capturing reporter seeing all of the other reporter's output.
  * The file based redirect no longer opens up a new temporary file for each partial test case run, so it will not run out of temporary files when running many tests in single process.
=== Miscellaneous ===
* Better documentation for matchers on thrown exceptions (`REQUIRE_THROWS_MATCHES`)
* Improved `catch_discover_tests`'s handling of environment paths (#2878)
  * It won't reorder paths in `DL_PATHS` or `DYLD_FRAMEWORK_PATHS` args
  * It won't overwrite the environment paths for test discovery

v3.6.0
=== Fixes ===
* Fixed Windows ARM64 build by fixing the preprocessor condition guarding use `_umul128` intrinsic.
* Fixed Windows ARM64EC build by removing intrinsic pragma it does not understand. (#2858)
  * Why doesn't the x64-emulation build mode understand x64 pragmas? Don't ask me, ask the MSVC guys.
* Fixed the JUnit reporter sometimes crashing when reporting a fatal error. (#1210, #2855)
  * The binary will still exit, but through the original error, rather than secondary error inside the reporter.
  * The underlying fix applies to all reporters, not just the JUnit one, but only JUnit was currently causing troubles.
=== Improvements ===
* Disable `-Wnon-virtual-dtor` in Decomposer and Matchers (#2854)
* `precision` in floating point stringmakers defaults to `max_digits10`.
  * This means that floating point values will be printed with enough precision to disambiguate any two floats.
* Column wrapping ignores ansi colour codes when calculating string width (#2833, #2849)
  * This makes the output much more readable when the provided messages contain colour codes.
=== Miscellaneous ===
* Conan support improvements
  * `compatibility_cppstr` is set to False. (#2860)
    * This means that Conan won't let you mix library and project with different C++ standard settings.
  * The implementation library CMake target name through Conan is properly set to `Catch2::Catch2` (#2861)
* `SelfTest` target can be built through Bazel (#2857)

v3.5.4
--- Fixes ---
* Fixed potential compilation error when asked to generate random integers whose type did not match `std::(u)int*_t`.
  * This manifested itself when generating random `size_t`s on MacOS
* Added missing outlined destructor causing `Wdelete-incomplete` when compiling against libstdc++ in C++23 mode (#2852)
* Fixed regression where decomposing assertion with const instance of `std::foo_ordering` would not compile
--- Improvements ---
* Reintroduced support for GCC 5 and 6 (#2836)
  * As with VS2017, if they start causing trouble again, they will be dropped again.
* Added workaround for targetting newest MacOS (Sonoma) using GCC (#2837, #2839)
* `CATCH_CONFIG_DEFAULT_REPORTER` can now be an arbitrary reporter spec
  * Previously it could only be a plain reporter name, so it was impossible to compile in custom arguments to the reporter.
* Improved performance of generating 64bit random integers by 20+%
--- Miscellaneous ---
* Significantly improved Conan in-tree recipe (#2831)
* `DL_PATHS` in `catch_discover_tests` now supports multiple arguments (#2852, #2736)
* Fixed preprocessor logic for checking whether we expect reproducible floating point results in tests.
* Improved the floating point tests structure to avoid `Wunused` when the reproducibility tests are disabled (#2845)

v3.5.3
=== Fixes ===
* Fixed OOB access when computing filename tag (from the `-#` flag) for file without extension (#2798)
* Fixed the linking against `log` on Android to be `PRIVATE` (#2815)
* Fixed `Wuseless-cast` in benchmarking internals (#2823)
=== Improvements ===
* Restored compatibility with VS2017 (#2792, #2822)
  * The baseline for Catch2 is still C++14 with some reasonable workarounds for specific compilers, so if VS2017 starts acting up again, the support will be dropped again.
* Suppressed clang-tidy's `bugprone-chained-comparison` in assertions (#2801)
* Improved the static analysis mode to evaluate arguments to `TEST_CASE` and `SECTION` (#2817)
  * Clang-tidy should no longer warn about runtime arguments to these macros being unused in static analysis mode.
  * Clang-tidy can warn on issues involved arguments to these macros.
* Added support for literal-zero detectors based on `consteval` constructors
  * This is required for compiling `REQUIRE((a <=> b) == 0)` against MSVC's stdlib.
  * Sadly, MSVC still cannot compile this assertion as it does not implement C++20 correctly.
  * You can use `clang-cl` with MSVC's stdlib instead.
  * If for some godforsaken reasons you want to understand this better, read the two relevant commits: [`dc51386b9fd61f99ea9c660d01867e6ad489b403`](dc51386), and [`0787132fc82a75e3fb255aa9484ca1dc1eff2a30`](0787132).
=== Miscellaneous ===
* Disabled tests for FP random generator reproducibility on non-SSE2 x86 targets (#2796)
* Modified the in-tree Conan recipe to support Conan 2 (#2805)

3.5.1
=== Fixes ===
* Fixed `-Wsubobject-linkage` in the Console reporter (#2794)
* Fixed adding new CLI Options to lvalue parser using `|` (#2787)

v3.5.1
=== Improvements ===
* Significantly improved performance of the CLI parsing.
  * This includes the cost of preparing the CLI parser, so Catch2's binaries start much faster.
=== Miscellaneous ===
* Added support for Bazel modules (#2781)
* Added CMake option to disable the build reproducibility settings (#2785)
* Added `log` library linking to the Meson build (#2784)