@RepeatedTest and RepetitionInfo are byte-for-byte unchanged between JUnit Jupiter 5.10.1 and 6.1.3 — confirmed here with javap against the real jars, not assumed from a changelog. The "JUnit 5 → 6" part of this module's story is almost entirely a version-number story: JUnit 6 unified versioning across Platform, Jupiter and Vintage (they all now share one release number, confirmed against the real maven-metadata.xml for all three artifacts) and raised the minimum Java version to 17. Nothing about @RepeatedTest itself had to change for that.

What did need fixing is what the previous version of this post got wrong or left out, each verified against a real jar, a real sources jar, or a real run rather than against prose:

{shortDisplayname} is not a real placeholder. There are exactly three: DISPLAY_NAME_PLACEHOLDER, CURRENT_REPETITION_PLACEHOLDER, TOTAL_REPETITIONS_PLACEHOLDER (confirmed via javap on RepeatedTest.class). A name() pattern containing the bogus token is accepted at compile time and left completely unresolved at run time — see docs/output/03-bogus-placeholder-scratch.txt.
RepetitionInfo carries four accessors, not two. getFailureCount() and getFailureThreshold() have been on the interface since JUnit 5.10, the same release that added failureThreshold() itself.
RepetitionInfo can be injected into @BeforeEach/@AfterEach, not only into the @RepeatedTest method.
Once failureThreshold is reached, JUnit skips the remaining repetitions — it does not merely "stop" them, and they are never invoked at all. See docs/output/07-failure-threshold-skips-remaining.txt for the real console-tree output showing Failure threshold [2] exceeded against repetitions 9 and 10.

Self-correction made before this module was finished: the "flaky test detection" use case needs a reproducible failure, not real timing-dependent flakiness, so both demo scratch classes fail deterministically on fixed repetition numbers (4 and 8 of 10) rather than relying on actual race conditions. Both were run for real, their output captured, and then deleted — they were never meant to be part of the permanent green suite.

Versions

Dependency	Version	Verified against
JUnit Jupiter	6.1.3	`maven-metadata.xml` (`latest`/`release`), matching `junit-bom` and `junit-platform-launcher` — JUnit 6's unified versioning
AssertJ	3.27.7	`maven-metadata.xml`, `<release>`
Maven Surefire	3.6.0	this module's own build
JDK	25 (Temurin)	`java -version`, this module's own build

@RepeatedTest/RepetitionInfo class files are identical (via javap) across 5.10.1 and 6.1.3. getFailureCount()/getFailureThreshold() are absent in 5.9.3's RepeatedTest.class and present from 5.10.1 onward — the old post's "introduced in 5.10" claim for failureThreshold itself is correct; it just never documented these two accessors.

Quickstart

mvn test   # 14 tests, 0 failures

Test classes

Class	What it proves	Captured output
`ReliabilityTest`	The smallest `@RepeatedTest(5)`; real default display names resolved through injected `TestInfo`	`docs/output/01-basic-repetition.txt`
`CustomNameTest`	A custom `name()` pattern built from the three real placeholders	`docs/output/02-custom-display-name.txt`
`MetadataTest`	All four `RepetitionInfo` accessors, including the two the old post never covered	`docs/output/04-repetition-info-metadata.txt`
`LifecycleTest`	`@BeforeAll`/`@AfterAll` (once) vs `@BeforeEach`/`@AfterEach` (per repetition), plus `RepetitionInfo` injected into `@BeforeEach`/`@AfterEach`	`docs/output/05-lifecycle-order.txt`

Captured output

File	Contents
`docs/output/00-full-test-run.txt`	`mvn test` — all 4 committed classes, 14 tests, 0 failures
`docs/output/01-basic-repetition.txt`	`ReliabilityTest` — real default display names
`docs/output/02-custom-display-name.txt`	`CustomNameTest` — real custom display names
`docs/output/03-bogus-placeholder-scratch.txt`	Scratch run proving `{shortDisplayname}` is not a real placeholder and resolves to literal text
`docs/output/04-repetition-info-metadata.txt`	`MetadataTest` — all four `RepetitionInfo` accessors across 3 repetitions
`docs/output/05-lifecycle-order.txt`	`LifecycleTest` — real call order and totals across 3 repetitions
`docs/output/06-flaky-detected.txt`	Scratch run: no `failureThreshold` set — all 10 repetitions run even though 2 fail
`docs/output/07-failure-threshold-skips-remaining.txt`	Scratch run: `failureThreshold = 2` — repetitions 9 and 10 skipped after the 2nd failure

docs/output/03, 06 and 07 come from scratch classes (ScratchPlaceholderTest, FlakyDetectionDemoTest, FailureThresholdStopsRemainingDemoTest) that were written, run once for real evidence, and then deleted — they are not part of the committed suite, which stays green at 14/14. Re-run scripts/run-all.sh to see exactly how each transcript was produced.

What's sourced from documentation, not run here

The JUnit 6.0.0 release notes facts quoted in the post (minimum Java 17, Vintage deprecated, junit-platform-runner/junit-platform-jfr removal, MethodOrderer.Alphanumeric removal, @CsvSource moving to FastCSV) are quoted from the official JUnit 6.0.0 release notes, not exercised in this module — none of them touch @RepeatedTest or RepetitionInfo directly. Everything else above was compiled, run, or pulled directly from a real jar in this sitting.