PredictionIO Universal Recommender Engine - scala

Question

I have pulled "zephrax/docker-prediction.io-universal-recommender" docker image and follow the instruction in https://github.com/PredictionIO/template-scala-parallel-universal-recommendation, when I do pio build it stops in this line and not going on :
root#0016c0672bc4:/universal-recommender-0.6.0# pio build --verbose
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/PredictionIO-0.11.0-
incubating/lib/spark/pio-data-hdfs-assembly-0.11.0-
incubating.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/PredictionIO-0.11.0-
incubating/lib/pio-assembly-0.11.0-
incubating.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an
explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
[INFO] [Engine$] Using command '/PredictionIO-0.11.0-
incubating/sbt/sbt' at /universal-recommender-0.6.0 to build.
[INFO] [Engine$] If the path above is incorrect, this process will
fail.
[INFO] [Engine$] Uber JAR disabled, but current working directory does
not look like an engine project directory. Please delete lib/pio-
assembly-0.11.0-incubating.jar manually.
[INFO] [Engine$] Going to run: /PredictionIO-0.11.0-incubating/sbt/sbt
package assemblyPackageDependency in /universal-recommender-0.6.0
[INFO] [Engine$] [info] Loading project definition from /universal-
recommender-0.6.0/project
[INFO] [Engine$] [info] Updating {file:/universal-recommender-
0.6.0/project/}universal-recommender-0-6-0-build...
[INFO] [Engine$] [info] Resolving org.scalariform#sbt-
scalariform;1.6.0 ...
[info] Resolving org.scalariform#sbt-scalariform;1.6.0
...
what is the problem ? how can I find the log in this docker image?
thank you