From 3f9424fa3a81f41fdd1c2f1423d1b6c193c82520 Mon Sep 17 00:00:00 2001
From: Niels Pardon <par@zurich.ibm.com>
Date: Wed, 10 Jun 2026 15:33:20 +0200
Subject: [PATCH] build: bump google-java-format to 1.28.0 for JDK 22+
 compatibility

Spotless' google-java-format 1.23.0 calls com.sun.tools.javac internals
that changed after JDK 21, so `spotlessCheck` fails with
NoSuchMethodError (cascading to a Guava NoClassDefFoundError) when the
Gradle daemon runs on JDK 22+. CI and JDK 17 developers are unaffected,
which is why this only reproduced for some contributors locally.

- Bump the Java step's google-java-format 1.23.0 -> 1.28.0. 1.28.0 is the
  newest release that still runs on JDK 17 (1.29.0+ require JDK 21),
  matching the daemon/CI toolchain, so it works across JDK 17-25. It
  produces identical formatting (no reformatting needed).
- Pin build-logic's kotlin-dsl compilation to a Java 17 toolchain so the
  generated precompiled-script-plugin classes load on the daemon
  regardless of its JDK. Previously they were emitted as JDK 21 bytecode
  that a JDK 17 daemon could not load (UnsupportedClassVersionError).
- Size build-logic's Kotlin compile daemon heap. build-logic is an
  included build and does not inherit the root gradle.properties, so a
  cold compile otherwise OOMs.
---
 build-logic/build.gradle.kts  |  6 ++++++
 build-logic/gradle.properties |  5 +++++
 build.gradle.kts              | 10 +++++++---
 3 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100644 build-logic/gradle.properties

diff --git a/build-logic/build.gradle.kts b/build-logic/build.gradle.kts
index c390a1741..10a3b61bb 100644
--- a/build-logic/build.gradle.kts
+++ b/build-logic/build.gradle.kts
@@ -5,4 +5,10 @@ plugins {
 
 repositories { gradlePluginPortal() }
 
+// Pin the precompiled-script-plugin compilation to Java 17 so the generated plugin classes load on
+// the daemon regardless of which JDK it runs on. Without this, kotlin-dsl targets whatever JDK the
+// daemon happens to use (e.g. 21/25), emitting newer bytecode that a Java 17 daemon cannot load
+// (UnsupportedClassVersionError).
+kotlin { jvmToolchain(17) }
+
 spotless { kotlinGradle { ktfmt().googleStyle() } }
diff --git a/build-logic/gradle.properties b/build-logic/gradle.properties
new file mode 100644
index 000000000..5a91892ce
--- /dev/null
+++ b/build-logic/gradle.properties
@@ -0,0 +1,5 @@
+# build-logic is an included build, so it does NOT inherit the root gradle.properties; its Kotlin
+# compile daemon (which builds the precompiled script plugins) must be sized here. Without this the
+# cold compile fails with an OOM / "internal compiler error" and falls back to a slow no-daemon
+# compile. Raise -Xmx further if you still see those failures on a cold build.
+kotlin.daemon.jvmargs=-Xmx2g
diff --git a/build.gradle.kts b/build.gradle.kts
index 09c233805..26b9fa396 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -62,9 +62,13 @@ allprojects {
       kotlinGradle { ktfmt("0.61").googleStyle() }
       java {
         target("src/*/java/**/*.java")
-        // since kfmt also brings in google-java-format we need to sync versions
-        // https://github.com/facebook/ktfmt/blob/v0.61/gradle/libs.versions.toml#L7
-        googleJavaFormat("1.23.0")
+        // google-java-format 1.28.0: earlier versions (e.g. 1.23.0, which ktfmt 0.61 bundles) call
+        // com.sun.tools.javac internals that changed in recent JDKs, so Spotless throws
+        // NoSuchMethodError/NoClassDefFoundError when the daemon runs on a newer JDK (e.g. 25).
+        // 1.28.0 is the newest release that still runs on JDK 17 (1.29.0+ requires JDK 21+),
+        // matching the daemon/CI toolchain. This Java step has its own formatter classpath,
+        // independent of ktfmt's bundled copy (used only for Kotlin), so they need not match.
+        googleJavaFormat("1.28.0")
         removeUnusedImports()
         trimTrailingWhitespace()
         forbidWildcardImports()