Bazel Scala "failed: Worker process did not return a WorkResponse"

Question

I am a beginner in Bazel and I need to migrate from sbt. I use Scala Rules to build my app.

I use the following dependencies with following aliases (to prevent typos):

Alias	Group	Artifact	Version
borer_core	io.bullet	borer-core_2.12	1.6.3
borer_derivation	io.bullet	borer-derivation_2.12	1.6.3
scala_logging	com.typesafe.scala-logging	scala-logging_2.12	3.9.2
logback	ch.qos.logback	logback-classic	1.2.3
tagging	com.softwaremill.common	tagging_2.12	2.2.1
ujson	com.lihaoyi	ujson_2.12	1.2.2

All these dependencies will be installed by JVM External Rules. It looks like so in Workspace:

dp_deps = [
    borer_core,
    borer_derivation,
    scala_logging,
    logback,
    tagging,
    ujson,
]

maven_install(
    name = "maven",
    artifacts = dp_deps,
    repositories = ["http://repo1.maven.org/maven/"],
    fetch_sources = True
)

Then I try to build a jar with scala_library in my BUILD file. It looks so:

scala_library(
    name = "some_lib",
    srcs = glob(["some_lib/src/main/**/*.scala"]),
    unused_dependency_checker_mode = 'warn',
    deps = [
        "@maven//:io_bullet_borer_core_2_12",
        "@maven//:io_bullet_borer_derivation_2_12",
        "@maven//:com_typesafe_scala_logging_scala_logging_2_12",
        "@maven//:ch_qos_logback_logback_classic",
        "@maven//:com_softwaremill_common_tagging_2_12",
        "@maven//:com_lihaoyi_ujson_2_12"
    ]
)

Then I try to build it with the following command:

bazel build //test-dir:some_lib --verbose_failures

and I receive the following Error with Log: Error:

ERROR: /Users/<edited>/test-dir/BUILD.bazel:136:14: scala //test-dir:some_lib failed: Worker process did not return a WorkResponse:

Log:

---8<---8<--- Start of log snippet, file at /private/var/tmp/_bazel_<edited>/07059176926c1842b8d4e633b0ddf1f4/bazel-workers/worker-7-Scalac.log ---8<---8<---
[... truncated ...]
scala.tools.nsc.typechecker.Macros$MacroExpander.expand(Macros.scala:622)
    at scala.tools.nsc.typechecker.Macros$MacroExpander.apply(Macros.scala:609)
    at scala.tools.nsc.typechecker.Macros.standardMacroExpand(Macros.scala:784)
    at scala.tools.nsc.typechecker.Macros.standardMacroExpand$(Macros.scala:782)
    at scala.tools.nsc.Global$$anon$4.standardMacroExpand(Global.scala:480)
    at scala.tools.nsc.typechecker.AnalyzerPlugins$$anon$10.default(AnalyzerPlugins.scala:457)
    at scala.tools.nsc.typechecker.AnalyzerPlugins$$anon$10.default(AnalyzerPlugins.scala:454)
    at scala.tools.nsc.typechecker.AnalyzerPlugins.invoke(AnalyzerPlugins.scala:411)
    at scala.tools.nsc.typechecker.AnalyzerPlugins.pluginsMacroExpand(AnalyzerPlugins.scala:454)
    at scala.tools.nsc.typechecker.AnalyzerPlugins.pluginsMacroExpand$(AnalyzerPlugins.scala:454)
    at scala.tools.nsc.Global$$anon$4.pluginsMacroExpand(Global.scala:480)
    at scala.tools.nsc.typechecker.Macros.macroExpand(Macros.scala:773)
    at scala.tools.nsc.typechecker.Macros.macroExpand$(Macros.scala:766)
    at scala.tools.nsc.Global$$anon$4.macroExpand(Global.scala:480)
    at scala.tools.nsc.typechecker.Typers$Typer.vanillaAdapt$1(Typers.scala:1164)
    at scala.tools.nsc.typechecker.Typers$Typer.adapt(Typers.scala:1227)
    at scala.tools.nsc.typechecker.Typers$Typer.adapt(Typers.scala:1200)
    at scala.tools.nsc.typechecker.Typers$Typer.adapt(Typers.scala:1220)
    at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5747)
    at scala.tools.nsc.typechecker.Typers$Typer.typedValDefImpl(Typers.scala:5949)
    at scala.tools.nsc.typechecker.Typers$Typer.typedValDef(Typers.scala:2056)
    at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5651)
    at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5733)
    at scala.tools.nsc.typechecker.Typers$Typer.typedStat$1(Typers.scala:5797)
    at scala.tools.nsc.typechecker.Typers$Typer.$anonfun$typedStats$10(Typers.scala:3357)
    at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:3357)
    at scala.tools.nsc.typechecker.Typers$Typer.typedTemplate(Typers.scala:2017)
    at scala.tools.nsc.typechecker.Typers$Typer.typedModuleDef(Typers.scala:1883)
    at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5654)
    at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5733)
    at scala.tools.nsc.typechecker.Typers$Typer.typedStat$1(Typers.scala:5797)
    at scala.tools.nsc.typechecker.Typers$Typer.$anonfun$typedStats$10(Typers.scala:3357)
    at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:3357)
    at scala.tools.nsc.typechecker.Typers$Typer.typedPackageDef$1(Typers.scala:5363)
    at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5656)
    at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5733)
    at scala.tools.nsc.typechecker.Analyzer$typerFactory$TyperPhase.apply(Analyzer.scala:115)
    at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:451)
    at scala.tools.nsc.typechecker.Analyzer$typerFactory$TyperPhase.run(Analyzer.scala:104)
    at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1501)
    at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1485)
    at scala.tools.nsc.Global$Run.compileSources(Global.scala:1478)
    at scala.tools.nsc.Global$Run.compile(Global.scala:1604)
    at scala.tools.nsc.Driver.doCompile(Driver.scala:47)
    at scala.tools.nsc.MainClass.doCompile(Main.scala:32)
    at scala.tools.nsc.Driver.process(Driver.scala:67)
    at io.bazel.rulesscala.scalac.ScalacWorker.compileScalaSources(ScalacWorker.java:226)
    at io.bazel.rulesscala.scalac.ScalacWorker.work(ScalacWorker.java:70)
    at io.bazel.rulesscala.worker.Worker.persistentWorkerMain(Worker.java:92)
    at io.bazel.rulesscala.worker.Worker.workerMain(Worker.java:46)
    at io.bazel.rulesscala.scalac.ScalacWorker.main(ScalacWorker.java:37)
Caused by: java.lang.ClassNotFoundException: io.bullet.borer.deriver.Deriver
    at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:588)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 75 more
---8<---8<--- End of log snippet, 2207 chars omitted ---8<---8<---
Target //test-dir:some_lib failed to build

How can I resolve this error? The io.bullet.borer.deriver.Deriver is in dependencies and classpath but JVM doesn't see it. Cannot log classpath of the sandbox, because bazel cannot get WorkerResponce. Please help me 😅.

Answer 1

I have found the problem. Default scala_toolchain has direct mode. So it sees only dependencies, that are defined in the deps filed of scala_library or scala_macro_library. So there are two options to solve this problem:

1. Add all needed direct dependencies to the deps array.
2. Or define own scala_toolchain - docs - example

So for the current example, we need to define all direct dependencies. By the way, they are already downloaded when you do maven_install. Now we need only reference them:

For borer additional dependencies will be:

• @maven//:io_bullet_borer_deriver_2_12

For scala_logging we need to add:

• @maven//:org_slf4j_slf4j_api

And for ujson we need:

• @maven//:com_lihaoyi_geny_2_12
• @maven//:com_lihaoyi_upickle_core_2_12

All fixes for the Github example repository are available in the repository under fix branches.

• Borer fix
• Spark fix