"javac returned nonzero exit code" error with no stacktrace or details in SBT 0.13.8+

[JoshRosen]

Consider the following invalid javacOptions config:

scalacOptions ++= Seq("-target:jvm-1.6"),
javacOptions ++= Seq("-source", "1.7", "-target", "1.6"),

With SBT 0.13.7, this results in the following error message:

[error] javac: source release 1.7 requires target release 1.7
[error] (compile:compile) javac returned nonzero exit code

In SBT 0.13.8+, on the other hand, the error details are missing, making this hard to debug:

[error] (compile:compileIncremental) javac returned nonzero exit code

I think that SBT's handling of javac error output must have changed in 0.13.8 because there are reports from other users that describe similar symptoms:

• https://groups.google.com/forum/#!msg/play-framework/UqNeFuoCZ0Q/GSTjBDV6CWcJ
• https://stackoverflow.com/questions/31132664/how-to-find-out-what-happened-when-sbt-says-javac-returned-nonzero-exit-code

[dwijnand]

Yes, things changed in 0.13.8 with #1702

[shajra]

Just curious, do you know when this is going to hit an SBT release? Is there a workaround? We've got at least one module that for now needs to be pure-Java, and this problem is kind of annoying. It feels weird pinning us to 0.13.7 just for this (though I'm not sure if we're really using any features in 0.13.8+ beyond bug fixes)

[eed3si9n]

@shajra Hopefully soon. You can try the nightly from here in the meantime - https://dl.bintray.com/sbt/ivy-snapshots/org.scala-sbt/sbt-launch/0.13.10-20151229-205306/

[shajra-cs]

@eed3si9n good to know. Using a nightly is probably more awkward than just downgrading temporarily to 0.13.7, but at least now I know where the nightlies are. Also, I have this thread of conversation to point coworkers to if they are curious about the state of things. Thanks.

[shajra-cs]

@eed3si9n actually, I shouldn't assume. What's the best way to use that URL for the SBT 0.13.10 snapshot? We're using Paul's "sbt-extras" script.

[eed3si9n]

I personally don't use the script, so I'm not sure if it works with the nightlies (it might you can try it first). My recommendation would be to try manual installation - http://www.scala-sbt.org/0.13/tutorial/Manual-Installation.html

[dwijnand]

@shajra-cogscale

Use -sbt-launch-repo https://repo.scala-sbt.org/scalasbt/ivy-snapshots.

Or you can use my branch: https://github.com/dwijnand/sbt-extras/tree/sbt-launch-snapshot-repo (diff)

[shajra-cs]

@dwijnand thanks, that's what I ended up doing. Also, I put in the snapshots repository in our proxy. I think that gets us through this until 0.13.10 properly releases.

[shajra-cs]

Okay, I played around with the snapshot release of 0.13.10, and I think it helps, but maybe doesn't solve the problem completely.

We're on Java 8, and turned on -Xlint:all to start with (which seems to have some non-standard reporting syntax), and here's some output shown for 0.13.7 that's still being suppressed with the 0.13.10 snapshot:

[error] warning: No processor claimed any of these annotations: com.fasterxml.jackson.annotation.JsonProperty,com.netflix.governator.annotations.Configuration,javax.ws.rs.ext.Provider,com.google.inject.Inject,javax.annotation.PreDestroy,lombok.extern.slf4j.Slf4j,com.google.inject.Provides,lombok.Data,javax.annotation.PostConstruct,com.fasterxml.jackson.annotation.JsonCreator,javax.annotation.Nullable,com.google.inject.Singleton
[error] error: warnings found and -Werror specified
[error] 1 error
[error] 1 warning
[error] (insights-web/compile:compile) javac returned nonzero exit code
[error] Total time: 26 s, completed Jan 3, 2016 2:49:52 PM

I think the fix doesn't catch this because it's not prefixed with "javac:", but I need to look at the patch and code more closely.

It kind of sucks that we're matching on strings. Perhaps we need to include "warning:" and "error:" in the match too?

[shajra-cs]

Just a note, this particular warning is suppressed with -Xlint:all,-processing. I think I really need to make a minimal project that fails for each of the checks in javac's -Xlint, so we can see that we've captured everything with any fix.