test_netrc, test_pep646_syntax and test_xml_etree now return resultsin the test_main() function.Changes:* Rewrite TestResult as a dataclass with a new State class.* Add test.support.TestStats class and Regrtest.stats_dict attribute.* libregrtest.runtest functions now modify a TestResult instance  in-place.* libregrtest summary lists the number of run tests and skipped  tests, and denied resources.* Add TestResult.has_meaningful_duration() method.* Compute TestResult duration in the upper function.* Use time.perf_counter() instead of time.monotonic().* Regrtest: rename 'resource_denieds' attribute to 'resource_denied'.* Rename CHILD_ERROR to MULTIPROCESSING_ERROR.* Use match/case syntadx to have different code depending on the  test state.(cherry picked from commitd4e534c)Co-authored-by: Victor Stinner <vstinner@python.org>Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

test_netrc, test_pep646_syntax and test_xml_etree now return resultsin the test_main() function.Changes:* Rewrite TestResult as a dataclass with a new State class.* Add test.support.TestStats class and Regrtest.stats_dict attribute.* libregrtest.runtest functions now modify a TestResult instance  in-place.* libregrtest summary lists the number of run tests and skipped  tests, and denied resources.* Add TestResult.has_meaningful_duration() method.* Compute TestResult duration in the upper function.* Use time.perf_counter() instead of time.monotonic().* Regrtest: rename 'resource_denieds' attribute to 'resource_denied'.* Rename CHILD_ERROR to MULTIPROCESSING_ERROR.* Use match/case syntadx to have different code depending on the  test state.Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>(cherry picked from commitd4e534c)

test_netrc, test_pep646_syntax and test_xml_etree now return resultsin the test_main() function.Changes:* Rewrite TestResult as a dataclass with a new State class.* Add test.support.TestStats class and Regrtest.stats_dict attribute.* libregrtest.runtest functions now modify a TestResult instance  in-place.* libregrtest summary lists the number of run tests and skipped  tests, and denied resources.* Add TestResult.has_meaningful_duration() method.* Compute TestResult duration in the upper function.* Use time.perf_counter() instead of time.monotonic().* Regrtest: rename 'resource_denieds' attribute to 'resource_denied'.* Rename CHILD_ERROR to MULTIPROCESSING_ERROR.* Use match/case syntadx to have different code depending on the  test state.Notes on the backport: doctest.TestResults.skipped is a new featurein Python 3.13, so don't use it in the backport.Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>(cherry picked from commitd4e534c)

test_netrc, test_pep646_syntax and test_xml_etree now return resultsin the test_main() function.Changes:* Rewrite TestResult as a dataclass with a new State class.* Add test.support.TestStats class and Regrtest.stats_dict attribute.* libregrtest.runtest functions now modify a TestResult instance  in-place.* libregrtest summary lists the number of run tests and skipped  tests, and denied resources.* Add TestResult.has_meaningful_duration() method.* Compute TestResult duration in the upper function.* Use time.perf_counter() instead of time.monotonic().* Regrtest: rename 'resource_denieds' attribute to 'resource_denied'.* Rename CHILD_ERROR to MULTIPROCESSING_ERROR.* Use match/case syntadx to have different code depending on the  test state.Notes on the backport: doctest.TestResults.skipped is a new featurein Python 3.13, so don't use it in the backport.Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>(cherry picked from commitd4e534c)

…108820)* Revert "[3.11]gh-101634: regrtest reports decoding error as failed test (#106169) (#106175)"This reverts commitd5418e9.* Revert "[3.11]bpo-46523: fix tests rerun when `setUp[Class|Module]` fails (GH-30895) (GH-103342)"This reverts commitecb09a8.* Revert "gh-95027: Fix regrtest stdout encoding on Windows (GH-98492)"This reverts commitb2aa28e.* Revert "[3.11]gh-94026: Buffer regrtest worker stdout in temporary file (GH-94253) (GH-94408)"This reverts commit0122ab2.* Revert "Run Tools/scripts/reindent.py (GH-94225)"This reverts commitf0f3a42.* Revert "gh-94052: Don't re-run failed tests with --python option (GH-94054)"This reverts commit1347607.* Revert "[3.11]gh-84461: Fix Emscripten umask and permission issues (GH-94002) (GH-94006)"This reverts commit1073184.*gh-93353: regrtest checks for leaked temporary files (#93776)When running tests with -jN, create a temporary directory per processand mark a test as "environment changed" if a test leaks a temporaryfile or directory.(cherry picked from commite566ce5)*gh-93353: Fix regrtest for -jN with N >= 2 (GH-93813)(cherry picked from commit36934a1)*gh-93353: regrtest supports checking tmp files with -j2 (#93909)regrtest now also implements checking for leaked temporary files anddirectories when using -jN for N >= 2. Use tempfile.mkdtemp() tocreate the temporary directory. Skip this check on WASI.(cherry picked from commit4f85cec)*gh-84461: Fix Emscripten umask and permission issues (GH-94002)- Emscripten's default umask is too strict, seeemscripten-core/emscripten#17269- getuid/getgid and geteuid/getegid are stubs that always return 0  (root). Disable effective uid/gid syscalls and fix tests that use  chmod() current user.- Cannot drop X bit from directory.(cherry picked from commit2702e40)*gh-94052: Don't re-run failed tests with --python option (#94054)(cherry picked from commit0ff7b99)* Run Tools/scripts/reindent.py (#94225)Reindent files which were not properly formatted (PEP 8: 4 spaces).Remove also some trailing spaces.(cherry picked from commite87ada4)*gh-94026: Buffer regrtest worker stdout in temporary file (GH-94253)Co-authored-by: Victor Stinner <vstinner@python.org>(cherry picked from commit199ba23)*gh-96465: Clear fractions hash lru_cache under refleak testing (GH-96689)Automerge-Triggered-By: GH:zware(cherry picked from commit9c8f379)*gh-95027: Fix regrtest stdout encoding on Windows (#98492)On Windows, when the Python test suite is run with the -jN option,the ANSI code page is now used as the encoding for the stdouttemporary file, rather than using UTF-8 which can lead to decodingerrors.(cherry picked from commitec1f6f5)*gh-98903: Test suite fails with exit code 4 if no tests ran (#98904)The Python test suite now fails wit exit code 4 if no tests ran. Itshould help detecting typos in test names and test methods.* Add "EXITCODE_" constants to Lib/test/libregrtest/main.py.* Fix a typo: "NO TEST RUN" becomes "NO TESTS RAN"(cherry picked from commitc76db37)*gh-100086: Add build info to test.libregrtest (#100093)The Python test runner (libregrtest) now logs Python build information like"debug" vs "release" build, or LTO and PGO optimizations.(cherry picked from commit3c89202)*bpo-46523: fix tests rerun when `setUp[Class|Module]` fails (#30895)Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>Co-authored-by: Łukasz Langa <lukasz@langa.pl>(cherry picked from commit9953860)*gh-82054: allow test runner to split test_asyncio to execute in parallel by sharding. (#103927)This runs test_asyncio sub-tests in parallel using sharding from Cinder. This suite is typically the longest-pole in runs because it is a test package with a lot of further sub-tests otherwise run serially. By breaking out the sub-tests as independent modules we can run a lot more in parallel.After porting we can see the direct impact on a multicore system.Without this change:  Running make test is 5 min 26 secondsWith this change:  Running make test takes 3 min 39 secondsThat'll vary based on system and parallelism. On a `-j 4` run similar to what CI and buildbot systems often do, it reduced the overall test suite completion latency by 10%.The drawbacks are that this implementation is hacky and due to the sorting of the tests it obscures when the asyncio tests occur and involves changing CPython test infrastructure but, the wall time saved it is worth it, especially in low-core count CI runs as it pulls a long tail. The win for productivity and reserved CI resource usage is significant.Future tests that deserve to be refactored into split up suites to benefit from are test_concurrent_futures and the way the _test_multiprocessing suite gets run for all start methods. As exposed by passing the -o flag to python -m test to get a list of the 10 longest running tests.---------Co-authored-by: Carl Meyer <carl@oddbird.net>Co-authored-by: Gregory P. Smith <greg@krypto.org> [Google, LLC](cherry picked from commit9e011e7)* Display the sanitizer config in the regrtest header. (#105301)Display the sanitizers present in libregrtest.Having this in the CI output for tests with the relevant environmentvariable displayed will help make it easier to do what we need tocreate an equivalent local test run.(cherry picked from commit852348a)*gh-101634: regrtest reports decoding error as failed test (#106169)When running the Python test suite with -jN option, if a worker stdoutcannot be decoded from the locale encoding report a failed testn so theexitcode is non-zero.(cherry picked from commit2ac3eec)*gh-108223: test.pythoninfo and libregrtest log Py_NOGIL (#108238)Enable with --disable-gil --without-pydebug:    $ make pythoninfo|grep NOGIL    sysconfig[Py_NOGIL]: 1    $ ./python -m test    ...    == Python build: nogil debug    ...(cherry picked from commit5afe0c1)*gh-90791: test.pythoninfo logs ASAN_OPTIONS env var (#108289)* Cleanup libregrtest code logging ASAN_OPTIONS.* Fix a typo on "ASAN_OPTIONS" vs "MSAN_OPTIONS".(cherry picked from commit3a1ac87)*gh-108388: regrtest splits test_asyncio package (#108393)Currently, test_asyncio package is only splitted into sub-tests whenusing command "./python -m test". With this change, it's alsosplitted when passing it on the command line:"./python -m test test_asyncio".Remove the concept of "STDTESTS". Python is now mature enough to nothave to bother with that anymore. Removing STDTESTS simplify thecode.(cherry picked from commit174e9da)* regrtest computes statistics (#108793)test_netrc, test_pep646_syntax and test_xml_etree now return resultsin the test_main() function.Changes:* Rewrite TestResult as a dataclass with a new State class.* Add test.support.TestStats class and Regrtest.stats_dict attribute.* libregrtest.runtest functions now modify a TestResult instance  in-place.* libregrtest summary lists the number of run tests and skipped  tests, and denied resources.* Add TestResult.has_meaningful_duration() method.* Compute TestResult duration in the upper function.* Use time.perf_counter() instead of time.monotonic().* Regrtest: rename 'resource_denieds' attribute to 'resource_denied'.* Rename CHILD_ERROR to MULTIPROCESSING_ERROR.* Use match/case syntadx to have different code depending on the  test state.Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>(cherry picked from commitd4e534c)*gh-108822: Add Changelog entry for regrtest statistics (#108821)---------Co-authored-by: Christian Heimes <christian@python.org>Co-authored-by: Zachary Ware <zach@python.org>Co-authored-by: Nikita Sobolev <mail@sobolevn.me>Co-authored-by: Joshua Herman <zitterbewegung@gmail.com>Co-authored-by: Gregory P. Smith <greg@krypto.org>

gh-108822: regrtest computes statistics (#108793)test_netrc, test_pep646_syntax and test_xml_etree now return resultsin the test_main() function.Changes:* Rewrite TestResult as a dataclass with a new State class.* Add test.support.TestStats class and Regrtest.stats_dict attribute.* libregrtest.runtest functions now modify a TestResult instance  in-place.* libregrtest summary lists the number of run tests and skipped  tests, and denied resources.* Add TestResult.has_meaningful_duration() method.* Compute TestResult duration in the upper function.* Use time.perf_counter() instead of time.monotonic().* Regrtest: rename 'resource_denieds' attribute to 'resource_denied'.* Rename CHILD_ERROR to MULTIPROCESSING_ERROR.* Use match/case syntadx to have different code depending on the  test state.Notes on the backport: doctest.TestResults.skipped is a new featurein Python 3.13, so don't use it in the backport.Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>(cherry picked from commitd4e534c)