预测 IO：构建，未找到引擎

Question

按照https://predictionio.incubator.apache.org/templates/recommendation/quickstart/ 上的快速入门（适用于 0.11.1 构建）后，我未能构建模板/引擎（我尝试构建 MyRecommendation 和另一个 NLP 模板）。 pio build --verbose 以 :

结尾

[INFO] [Engine$] Compilation finished successfully.
[INFO] [Engine$] Looking for an engine...
[ERROR] [Engine$] No engine found. Your build might have failed. Aborting.

当我尝试运行 pio train 时失败：

Exception in thread "main" scala.ScalaReflectionException: object org.example.recommendation.RecommendationEngine not found.

监听器运行正常（也可以通过curl拉取数据），pio status：

[INFO] [Management$] Inspecting PredictionIO...
[INFO] [Management$] PredictionIO 0.11.1-SNAPSHOT is installed at /home/us/proj/incubator-predictionio/PredictionIO-0.11.1-SNAPSHOT
[INFO] [Management$] Inspecting Apache Spark...
[INFO] [Management$] Apache Spark is installed at /home/us/proj/incubator-predictionio/PredictionIO-0.11.1-SNAPSHOT/vendors/spark-2.1.1-bin-hadoop2.6
[INFO] [Management$] Apache Spark 2.1.1 detected (meets minimum requirement of 1.3.0)
[INFO] [Management$] Inspecting storage backend connections...
[INFO] [Storage$] Verifying Meta Data Backend (Source: PGSQL)...
[INFO] [Storage$] Verifying Model Data Backend (Source: PGSQL)...
[INFO] [Storage$] Verifying Event Data Backend (Source: PGSQL)...
[INFO] [Storage$] Test writing to Event Store (App Id 0)...
[INFO] [Management$] Your system is all ready to go.

有什么想法吗？

Answer 1

在您的 build.sbt 示例中指定您的 scala 版本

scalaVersion := "2.11.8"