I'm compiling a project that has 77 Scala files with scala 2.10.5.
I got 0 warning and 1 weird error message:
[ERROR] type mismatch;
found : Array[?B]
required: scala.collection.GenTraversableOnce[?]
Note that implicit conversions are not applicable because they are ambiguous:
both method booleanArrayOps in object Predef of type (xs: Array[Boolean])scala.collection.mutable.ArrayOps[Boolean]
and method byteArrayOps in object Predef of type (xs: Array[Byte])scala.collection.mutable.ArrayOps[Byte]
are possible conversion functions from Array[?B] to scala.collection.GenTraversableOnce[?]
[ERROR] one error found
[INFO] ------------------ ....{this line is irrelevant}
The error information doesn't indicate the location of the error, so I think this is a scalac internal error. What should I do to debug it?
Thanks a lot for any help.
UPDATES: I enabled debugging mode and see the full stack trace:
Caused by: Compilation failed
at sbt.compiler.AnalyzingCompiler.call(AnalyzingCompiler.scala:105)
at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:48)
at sbt.compiler.AnalyzingCompiler.compile(AnalyzingCompiler.scala:41)
at sbt.compiler.AggressiveCompile$$anonfun$3$$anonfun$compileScala$1$1.apply$mcV$sp(AggressiveCompile.scala:99)
at sbt.compiler.AggressiveCompile$$anonfun$3$$anonfun$compileScala$1$1.apply(AggressiveCompile.scala:99)
at sbt.compiler.AggressiveCompile$$anonfun$3$$anonfun$compileScala$1$1.apply(AggressiveCompile.scala:99)
at sbt.compiler.AggressiveCompile.sbt$compiler$AggressiveCompile$$timed(AggressiveCompile.scala:166)
at sbt.compiler.AggressiveCompile$$anonfun$3.compileScala$1(AggressiveCompile.scala:98)
at sbt.compiler.AggressiveCompile$$anonfun$3.apply(AggressiveCompile.scala:143)
at sbt.compiler.AggressiveCompile$$anonfun$3.apply(AggressiveCompile.scala:87)
at sbt.inc.IncrementalCompile$$anonfun$doCompile$1.apply(Compile.scala:39)
at sbt.inc.IncrementalCompile$$anonfun$doCompile$1.apply(Compile.scala:37)
at sbt.inc.IncrementalCommon.cycle(Incremental.scala:99)
at sbt.inc.Incremental$$anonfun$1.apply(Incremental.scala:38)
at sbt.inc.Incremental$$anonfun$1.apply(Incremental.scala:37)
at sbt.inc.Incremental$.manageClassfiles(Incremental.scala:65)
at sbt.inc.Incremental$.compile(Incremental.scala:37)
at sbt.inc.IncrementalCompile$.apply(Compile.scala:27)
at sbt.compiler.AggressiveCompile.compile2(AggressiveCompile.scala:157)
at sbt.compiler.AggressiveCompile.compile1(AggressiveCompile.scala:71)
at com.typesafe.zinc.Compiler.compile(Compiler.scala:184)
at com.typesafe.zinc.Compiler.compile(Compiler.scala:164)
at sbt_inc.SbtIncrementalCompiler.compile(SbtIncrementalCompiler.java:92)
at scala_maven.ScalaCompilerSupport.incrementalCompile(ScalaCompilerSupport.java:303)
at scala_maven.ScalaCompilerSupport.compile(ScalaCompilerSupport.java:119)
at scala_maven.ScalaCompilerSupport.doExecute(ScalaCompilerSupport.java:99)
at scala_maven.ScalaMojoSupport.execute(ScalaMojoSupport.java:482)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
... 21 more
Is this helpful in identifying the problem?
OK I found a solution:
scalac 2.10.5 had a glitch on printing out the line number of the error, which is indeed a syntax error in my code.
When I switched to scalac 2.11.7 the line number is printed out, which makes it easy to fix the problem