Upgrade to Gradle 9.3.1 with JDK 21 build requirement #365

jbachorik · 2026-02-11T13:12:03Z

What does this PR do?:

Upgrades the build system from Gradle 8.12 to Gradle 9.3.1 and updates the build JDK requirement from JDK 11 to JDK 21. Also adds Dependabot configuration for automated dependency updates.

Key changes:

Gradle 8.12 → 9.3.1
Spotless plugin 6.x → 7.0.2
JMH plugin 0.7.2 → 0.7.3
CI and Docker builds now use JDK 21 (Gradle 9 requires JDK 17+)
Fix Kotlin 2.2 API changes (capitalize, createTempFile, exec)
Fix Spotless 7.x API changes (editorConfigOverride, leadingTabsToSpaces)
Two-JDK pattern: build with JDK 21, test with configurable JDK
Migrate Test/JavaExec tasks to Exec tasks to bypass Gradle 9 toolchain compatibility issues on musl systems
Fix Exec task JDK resolution: defer executable lookup to execution time so JAVA_TEST_HOME is read correctly
Fix Exec task environment: explicitly pass through CI environment variables (LIBC, TEST_COMMIT, etc.)
Test filtering now uses -Ptests property instead of --tests flag (Exec tasks don't support --tests)
Add Dependabot for Gradle and GitHub Actions dependency updates

Motivation:

Gradle 9 brings performance improvements, better dependency management, and is required for long-term support. JDK 21 is the current LTS and provides the best tooling support while still allowing --release 8 targeting.

Additional Notes:

The compiled bytecode still targets Java 8 runtime (unchanged)
JDK 21+ emits deprecation warnings for --release 8; suppressed with -Xlint:-options
Build JDK configuration documented in AGENTS.md for future reference
Config-specific test tasks (testdebug, testrelease) use Exec task type to bypass Gradle's toolchain system, which has musl compatibility issues
Exec tasks differ from Test tasks: executable and environment must be resolved at execution time, not configuration time
Dependabot will create weekly PRs for Gradle and GitHub Actions updates

How to test the change?:

Run gradle build - should complete successfully
Run gradle spotlessCheck - formatting checks pass
Run gradle test with -Ptests filter - test filtering works
Run with JAVA_TEST_HOME set - multi-JDK testing works
Run utils/run-docker-tests.sh --libc=musl --jdk=21 - Docker tests work on musl (Alpine)
CI pipeline should pass with correct JDK versions for each test matrix combination

For Datadog employees:

If this PR touches code that signs or publishes builds or packages, or handles
credentials of any kind, I've requested a review from @DataDog/security-design-and-guidance.
This PR doesn't touch any of that.
JIRA: [JIRA-XXXX]

Unsure? Have a question? Request a review!

🤖 Generated with Claude Code

- Gradle 8.12 → 9.3.1, Spotless 7.0.2, JMH 0.7.3 - CI and Docker builds now use JDK 21 (Gradle 9 requires JDK 17+) - Fix Kotlin 2 API changes (capitalize, createTempFile, exec) - Fix Spotless 7.x API changes (editorConfigOverride, leadingTabsToSpaces) - Two-JDK pattern: build JDK 21, test JDK configurable 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dd-octo-sts · 2026-02-11T13:13:02Z

CI Test Results

Run: #21947336544 | Commit: 04028e4 | Duration: 19m 41s (longest job)

❌ 5 of 40 test jobs failed

Status Overview

JDK	glibc-aarch64/debug	glibc-amd64/debug	musl-aarch64/debug	musl-amd64/debug
8	-	✅	-	-
8-ibm	-	✅	-	-
8-j9	✅	✅	-	-
8-librca	-	-	❌	❌
8-orcl	-	✅	-	-
8-zing	✅	✅	-	-
11	-	✅	-	-
11-j9	✅	✅	-	-
11-librca	-	-	❌	❌
11-zing	✅	✅	-	-
17	✅	✅	-	-
17-graal	✅	✅	-	-
17-j9	✅	✅	-	-
17-librca	-	-	✅	✅
17-zing	✅	✅	-	-
21	❌	✅	-	-
21-graal	✅	✅	-	-
21-librca	-	-	✅	✅
21-zing	✅	✅	-	-
25	✅	✅	-	-
25-graal	✅	✅	-	-
25-librca	-	-	✅	✅

Legend: ✅ passed | ❌ failed | ⚪ skipped | 🚫 cancelled