Scala compiler error: unknown option: '-dd'
  Scala compiler -help  gives more information
Usage: scalac <options | source files>
where possible options include: 
  -doc                            Generate documentation
  -g                              Generate debugging info
  -nowarn                         Generate no warnings
  -noassert                       Generate no assertions and assumptions
  -verbose                        Output messages about what the compiler is doing
  -classpath <path>               Specify where to find user class files
  -sourcepath <path>              Specify where to find input source files
  -bootclasspath <path>           Override location of bootstrap class files
  -extdirs <dirs>                 Override location of installed extensions
  -d <directory>                  Specify where to place generated class files
  -encoding <encoding>            Specify character encoding used by source files
  -windowtitle <windowtitle>      Specify window title of generated HTML documentation
  -documenttitle <documenttitle>  Specify document title of generated HTML documentation
  -target:<target>                Specify which backend to use (jvm-1.5,jvm-1.4,msil,cldc)
  -migrate                        Assist in migrating from Scala version 1.0
  -debug                          Output debugging messages
  -statistics                     Print compiler statistics
  -explaintypes                   Explain type errors in more detail
  -resident                       Compiler stays resident, files to compile are read from standard input
  -uniqid                         Print identifiers with unique names (debugging option)
  -printtypes                     Print tree types (debugging option)
  -prompt                         Display a prompt after each error (debugging option)
  -noimports                      Compile without any implicit imports
  -nopredefs                      Compile without any implicit predefined values
  -skip:<phase>                   Skip <phase>
  -check:<phase>                  Check the tree at start of <phase>
  -print:<phase>                  Print out program after <phase>
  -printer:<printer>              Printer to use (text,html)
  -printfile <file>               Specify file in which to print trees
  -graph:<phase>                  Graph the program after <phase>
  -browse:<phase>                 Browse the abstract syntax tree after <phase>
  -stop:<phase>                   Stop after phase <phase>
  -log:<phase>                    Log operations in <phase>
  -version                        Print product version and exit
  -help                           Print a synopsis of standard options
  -Xinline                        Perform inlining when possible
  -Xcloselim                      Perform closure elimination
  -Xdce                           Perform dead code elimination
  -Xshowcls <class>               Show class info
  -Xshowobj <object>              Show object info
  -Xshowicode                     Print the generated ICode
  -Xgadt                          enable gadt for classes
  -Xlinearizer:<Xlinearizer>      Linearizer to use (normal,dfs,rpo)
  -Xgenerics                      Use generic Java types

one error found