java coverage crash on 4.0.0rc2

[alexeagle]

running bazel coverage //... in a big multi-lang monorepo.
Bazel version 37a429ad12b4c9e6a62dbae4881a1ff03b81ab40 (4.0.0-rc2)
rules_java at d43b0aa2d3b2173fcc54d3c194e89fa66cdc6e1a (current HEAD)

let me know if I can provide anything else short of a minimal repro

(21:13:45) FATAL: bazel crashed due to an internal error. Printing stack trace:
--
  | java.lang.RuntimeException: Unrecoverable error while evaluating node 'ConfiguredTargetKey{label=//test/java/com/rh/ledger:LedgerTest, config=BuildConfigurationValue.Key[f35c31b1baf1ab2bed1284160072656c995dfa7db8c9f4349087d4fbbb2e27de]}' (requested by nodes )
  | at com.google.devtools.build.skyframe.AbstractParallelEvaluator$Evaluate.run(AbstractParallelEvaluator.java:563)
  | at com.google.devtools.build.lib.concurrent.AbstractQueueVisitor$WrappedRunnable.run(AbstractQueueVisitor.java:398)
  | at java.base/java.util.concurrent.ForkJoinTask$AdaptedRunnableAction.exec(Unknown Source)
  | at java.base/java.util.concurrent.ForkJoinTask.doExec(Unknown Source)
  | at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source)
  | at java.base/java.util.concurrent.ForkJoinPool.scan(Unknown Source)
  | at java.base/java.util.concurrent.ForkJoinPool.runWorker(Unknown Source)
  | at java.base/java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source)
  | Caused by: java.lang.NullPointerException
  | at com.google.devtools.build.lib.rules.java.JavaCompilationHelper.addCoverageSupport(JavaCompilationHelper.java:382)
  | at com.google.devtools.build.lib.bazel.rules.java.BazelJavaSemantics.addCoverageSupport(BazelJavaSemantics.java:613)
  | at com.google.devtools.build.lib.rules.java.JavaBinary.create(JavaBinary.java:199)
  | at com.google.devtools.build.lib.rules.java.JavaBinary.create(JavaBinary.java:65)
  | at com.google.devtools.build.lib.analysis.ConfiguredTargetFactory.createRule(ConfiguredTargetFactory.java:381)
  | at com.google.devtools.build.lib.analysis.ConfiguredTargetFactory.createConfiguredTarget(ConfiguredTargetFactory.java:194)
  | at com.google.devtools.build.lib.skyframe.SkyframeBuildView.createConfiguredTarget(SkyframeBuildView.java:938)
  | at com.google.devtools.build.lib.skyframe.ConfiguredTargetFunction.createConfiguredTarget(ConfiguredTargetFunction.java:1013)
  | at com.google.devtools.build.lib.skyframe.ConfiguredTargetFunction.compute(ConfiguredTargetFunction.java:371)
  | at com.google.devtools.build.skyframe.AbstractParallelEvaluator$Evaluate.run(AbstractParallelEvaluator.java:477)
  | ... 7 more

[alexeagle]

From

bazel/src/main/java/com/google/devtools/build/lib/rules/java/JavaCompilationHelper.java

Line 382 in 37a429a

Artifact jacocoRunnerJar = jacocoRunner.getExecutable();

it looks like jacoco runner isn't in my Java toolchain. Seems like the conditional right above that line was meant to error out in this case, but fell through instead.

[alexeagle]

I see this was recently changed in 2936202

[jin]

cc @comius