protoc-gen-scala: program not found or is not executable

[pcalcado]

Hey,

This may not be a bug, so sorry if this is not the right place but I couldn't find a mailing list.

I am investigating ScalaPB as a replacement for sbtprotobuf and pure-Java classes.

When I run the generation command I get this:

> protobuf:protobufGenerate
[info] Compiling 2 protobuf files to /<snip>/server/target/scala-2.10/src_managed/main/compiled_protobuf,/<snip>/server/target/scala-2.10/src_managed/main/compiled_protobuf
[info] Compiling schema /<snip>/server/src/main/protobuf/abc.proto
[info] Compiling schema /<snip>/server/src/main/protobuf/soundcloud.proto
[error] protoc-gen-scala: program not found or is not executable
[error] --scala_out: protoc-gen-scala: Plugin failed with status code 1.
[trace] Stack trace suppressed: run 'last abc/protobuf:protobufGenerate' for the full output.
[error] (abc/protobuf:protobufGenerate) protoc returned exit code: 1
[error] Total time: 0 s, completed Dec 22, 2014 6:25:37 PM

Full output:

> last abc/protobuf:protobufGenerate
[info] Compiling 2 protobuf files to /<snip>/server/target/scala-2.10/src_managed/main/compiled_protobuf,/<snip>/server/target/scala-2.10/src_managed/main/compiled_protobuf
[debug] protoc options:
[debug]     --java_out=/<snip>/server/target/scala-2.10/src_managed/main/compiled_protobuf
[debug]     --scala_out=/<snip>/server/target/scala-2.10/src_managed/main/compiled_protobuf
[info] Compiling schema /<snip>/server/src/main/protobuf/abc.proto
[info] Compiling schema /<snip>/server/src/main/protobuf/soundcloud.proto
[error] protoc-gen-scala: program not found or is not executable
[error] --scala_out: protoc-gen-scala: Plugin failed with status code 1.
java.lang.RuntimeException: protoc returned exit code: 1
    at scala.sys.package$.error(package.scala:27)
    at sbtprotobuf.ProtobufPlugin$.sbtprotobuf$ProtobufPlugin$$compile(ProtobufPlugin.scala:86)
    at sbtprotobuf.ProtobufPlugin$$anonfun$sourceGeneratorTask$1$$anonfun$6.apply(ProtobufPlugin.scala:110)
    at sbtprotobuf.ProtobufPlugin$$anonfun$sourceGeneratorTask$1$$anonfun$6.apply(ProtobufPlugin.scala:109)
    at sbt.FileFunction$$anonfun$cached$1.apply(Tracked.scala:188)
    at sbt.FileFunction$$anonfun$cached$1.apply(Tracked.scala:188)
    at sbt.FileFunction$$anonfun$cached$2$$anonfun$apply$3$$anonfun$apply$4.apply(Tracked.scala:202)
    at sbt.FileFunction$$anonfun$cached$2$$anonfun$apply$3$$anonfun$apply$4.apply(Tracked.scala:198)
    at sbt.Difference.apply(Tracked.scala:177)
    at sbt.Difference.apply(Tracked.scala:158)
    at sbt.FileFunction$$anonfun$cached$2$$anonfun$apply$3.apply(Tracked.scala:198)
    at sbt.FileFunction$$anonfun$cached$2$$anonfun$apply$3.apply(Tracked.scala:197)
    at sbt.Difference.apply(Tracked.scala:177)
    at sbt.Difference.apply(Tracked.scala:152)
    at sbt.FileFunction$$anonfun$cached$2.apply(Tracked.scala:197)
    at sbt.FileFunction$$anonfun$cached$2.apply(Tracked.scala:195)
    at sbtprotobuf.ProtobufPlugin$$anonfun$sourceGeneratorTask$1.apply(ProtobufPlugin.scala:112)
    at sbtprotobuf.ProtobufPlugin$$anonfun$sourceGeneratorTask$1.apply(ProtobufPlugin.scala:107)
    at scala.Function7$$anonfun$tupled$1.apply(Function7.scala:35)
    at scala.Function7$$anonfun$tupled$1.apply(Function7.scala:34)
    at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
    at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:42)
    at sbt.std.Transform$$anon$4.work(System.scala:64)
    at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:237)
    at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:237)
    at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:18)
    at sbt.Execute.work(Execute.scala:244)
    at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:237)
    at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:237)
    at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:160)
    at sbt.CompletionService$$anon$2.call(CompletionService.scala:30)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
[error] (abc/protobuf:protobufGenerate) protoc returned exit code: 1

From all this I assume I need to have a plugin called protoc-gen-scala (I thought ScalaPB had its own plugin?). Google takes me to this project: https://github.com/ktoso/protoc-gen-scala, which seems quite old. Either way the build instructions there don't work for me either, so my question becomes: how do I setup protoc-gen-scala to work with ScalaPB?

Here is my plugins.sbt

addSbtPlugin("com.typesafe.sbt" % "sbt-start-script" % "0.10.0")

addSbtPlugin("net.virtual-void" % "sbt-dependency-graph" % "0.7.4")

addSbtPlugin("com.github.mpeltonen" % "sbt-idea" % "1.6.0")

addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "2.4.0")

addSbtPlugin("org.ensime" % "ensime-sbt-cmd" % "0.1.2")

addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "0.7.1")

addSbtPlugin("com.trueaccord.scalapb" % "sbt-scalapb" % "0.4.0")

And here are the relevant bits in Build.scala:

/...
import com.trueaccord.scalapb.{ScalaPbPlugin => PB}
/...
lazy val buildSettings = super.settings ++ Defaults.coreDefaultSettings ++ graphSettings ++ microserviceConfig ++ PB.protobufSettings

I've tried versions released before November and had the same issues.

Thanks!

[thesamet]

Hi Phil,

Just running "compile" will generate Scala sources and compile them,
If you want to just generate the sources without compiling them use:

protobuf:protobufScalaGenerate

I'll add some documentation for this, I figured most people would just invoke it through the 'compile' command. Also note that currently, the SBT plugin should work only on Unix-like systems.

[pcalcado]

Thanks, that's exactly what I was looking for!

Feel free to close the issue, I won't do it myself because you may want to use it to track the documentation work.

Cheers and congrats on the good work here.