kafka-streams: capture the ambiguous null tombstone compile error

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01RjfyTgmERTWLqzafu34Cth

kafka-streams/scripts/compile-broken.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# Captures the real javac error for the null-tombstone mistake into output/07-ambiguous-null-tombstone.txt
+set -uo pipefail
+cd "$(dirname "$0")/.."
+mvn -B -q dependency:build-classpath -Dmdep.outputFile=target/cp.txt >/dev/null
+mkdir -p target/broken
+javac -d target/broken -cp "$(cat target/cp.txt)" src/broken/AmbiguousNullTombstone.java 2>&1 \
+  | grep -v '^Picked up' > output/07-ambiguous-null-tombstone.txt
+cat output/07-ambiguous-null-tombstone.txt

kafka-streams/scripts/run-all.sh

@@ -4,4 +4,5 @@ set -euo pipefail
 cd "$(dirname "$0")/.."
 rm -f output/*.txt
 mvn -B -q test
+scripts/compile-broken.sh >/dev/null || true
 ls output