Part of Javac diagnostic messages are hidden

[retronym]

The following code in DiagnosticReporter:

zinc/internal/zinc-compile-core/src/main/scala/sbt/internal/inc/javac/DiagnosticsReporter.scala

Lines 34 to 56 in 494fdda

	private def fixedDiagnosticMessage(d: Diagnostic[_ <: JavaFileObject]): String = {
	def getRawMessage = d.getMessage(null)
	def fixWarnOrErrorMessage = {
	val tmp = getRawMessage
	// we fragment off the line/source/type report from the message.
	// NOTE - End of line handling may be off.
	val lines: Seq[String] =
	tmp.split(END_OF_LINE_MATCHER) match {
	case Array(head, tail @ _*) =>
	val newHead = head.split(":").last
	newHead +: tail
	case Array(head) =>
	head.split(":").last :: Nil
	case Array() => Seq.empty[String]
	}
	lines.mkString(EOL)
	}
	d.getKind match {
	case Diagnostic.Kind.ERROR | Diagnostic.Kind.WARNING | Diagnostic.Kind.MANDATORY_WARNING =>
	fixWarnOrErrorMessage
	case _ => getRawMessage
	}
	}

d.getMessage(null) = """module not found: acme.b"""
PositionImpl(d).toString = "/Users/jz/code/javafileman/acme.a/src/main/java/module-info.java:3"

And runs the result of getMessage through a regex translation, documented to remove the source file name and line number. But they don't exist in that string, and instead we strip half of the message:

fixWarnOrErrorMessage = " acme.b"

Which is reported to the user as:

[warn] /Users/jz/code/javafileman/acme.a/src/main/java/module-info.java:3:1:  acme.b
[warn]     exports acme.a.shared to acme.b;

I'm using Java 10, not sure yet if the behaviour of getMessage has changed, or it this is just a long standing bug that you only notice when an Java error or warning contains ':'

[retronym]

It's an old bug:

⚡ java -version
openjdk version "1.8.0-internal"
OpenJDK Runtime Environment (build 1.8.0-internal-jenkins_2017_07_27_21_17-b00)
OpenJDK 64-Bit Server VM (build 25.71-b00, mixed mode)

⚡ sbt compile
[info] Loading settings from dirtymoney.sbt,gpg.sbt,idea.sbt ...
[info] Loading global plugins from /Users/jz/.sbt/1.0/plugins
[info] Loading project definition from /private/tmp/javac-diagnostic/project
[info] Set current project to javac-diagnostic (in build file:/private/tmp/javac-diagnostic/)
[info] Executing in batch mode. For better performance use sbt's shell
[info] Compiling 1 Java source to /private/tmp/javac-diagnostic/target/scala-2.12/classes ...
[error] /private/tmp/javac-diagnostic/src/main/java/example/Test.java:4:1:  C.D
[error]         D.this.toString();
[error] (Compile / compileIncremental) javac returned non-zero exit code
[error] Total time: 0 s, completed 05/04/2018 12:52:16 PM

⚡ cat src/main/java/example/Test.java
class C {
    class D {}
    void test() {
        D.this.toString();
    }
}

⚡ javac src/main/java/example/Test.java
src/main/java/example/Test.java:4: error: not an enclosing class: C.D
        D.this.toString();
         ^
1 error

[dwijnand]

is this also #520 (which is as known as #376)?

[retronym]

You'd need to have a single javac error message line, ending in a :. Even then, I think you'd see [error] <blank>'. So I'd bet that's a different issue.