[-] .sbt

 |--[-] 0.13

 |   |--[-] plugins

 |   |   `----- plugins.sbt

 |   `----- global.sbt

 `----- repositories

addSbtPlugin("org.ensime" % "sbt-ensime" % "1.12.5")

import org.ensime.EnsimeCoursierKeys._

ensimeServerVersion in ThisBuild := "2.0.0-SNAPSHOT"

[repositories]

local

# osc: http://maven.oschina.net/content/groups/public/ # 已经不能使用了，使用阿里云替代

aliyun:http://maven.aliyun.com/nexus/content/groups/public/

maven-central:http://repo1.maven.org/maven2/

store_2:http://repo2.maven.org/maven2/

uk_mir:http://uk.maven.org/maven2/

store_mir:http://mirrors.ibiblio.org/maven2/

typesafe: http://dl.bintray.com/typesafe/ivy-releases/,[organization]/[module]/(scala_[scalaVersion]/)(sbt_[sbtVersion]/)[revision]/[type]s/[artifact](-[classifier]).[ext], bootOnly

sbt-releases-repo:http://repo.typesafe.com/typesafe/ivy-releases/, [organization]/[module]/(scala_[scalaVersion]/)(sbt_[sbtVersion]/)[revision]/[type]s/[artifact](-[classifier]).[ext]

sbt-plugins-repo:http://repo.scala-sbt.org/scalasbt/sbt-plugin-releases/, [organization]/[module]/(scala_[scalaVersion]/)(sbt_[sbtVersion]/)[revision]/[type]s/[artifact](-[classifier]).[ext]

(use-package sbt-mode

  :commands sbt-start sbt-command

  :init

  (setq

   sbt:prefer-nested-projects t

   sbt:scroll-to-bottom-on-output nil

   sbt:default-command ";compile ;test:compile ;it:compile")

  :config

  ;; WORKAROUND: https://github.com/hvesalai/sbt-mode/issues/31

  ;; allows using SPACE when in the minibuffer

  (substitute-key-definition

   'minibuffer-complete-word

   'self-insert-command

   minibuffer-local-completion-map)

  (bind-key "C-c c" 'sbt-command sbt:mode-map)

  (bind-key "C-c e" 'next-error sbt:mode-map))

https://coderwall.com/p/avlrna/emacs-ensime-for-your-scala-coding
http://blog.ssanj.net/posts/2011-04-06-ensime-with-emacs.html
构建工具和ensime配置工具，这里要分开来讲。一般构建工具和ensime配置插件是使用一套的。但有时，gradle的ensime配置插件过时了，sbt的ensime插件是由官方更新的，所以，总是和ensime配套升级的。所以，用sbt的插件进行配置总是可行的。但是，sbt是一个新的构建系统，所以，在基础的构建，如对springboot的支持中有时是不稳定的，这时使用Gradle或者Maven会更稳定。
结论：当sbt可以满足构建需求时，使用sbt是最方便的，既可以配置ensime，又可以构建。当sbt构建出问题时（极少数情况下），这时可以使用Gradle或者Maven来进行构建。
ensime的配置：

http://ensime.org/build_tools/sbt/

• install
  ~/.sbt/0.13/plugins/plugins.sbt

  addSbtPlugin("org.ensime" % "sbt-ensime" % "1.12.14")
  

  sbt ensimeConfig
  

http://ensime.org/build_tools/maven/

• install
  ~/.m2/settings.xml :

  <build>
  
    <pluginGroups>
  
      <pluginGroup>org.ensime.maven.plugins</pluginGroup>
  
    </pluginGroups>
  
  </build>
  

  国内加速使用阿里云镜像，在<build>节点下添加，这样速度就会快很多倍了：

  <mirrors>
  
      <mirror>
  
          <id>alimaven</id>
  
          <name>aliyun maven</name>
  
          <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
  
          <mirrorOf>central</mirrorOf>
  
      </mirror>
  
  </mirrors>
  

• use

  mvn ensime:generate
  

http://ensime.org/build_tools/gradle/

• install
  ~/.gradle/init.gradle

  apply plugin: AddEnsimePlugin
  
  class AddEnsimePlugin  implements Plugin<Gradle> {
  
    def supportedPlugins = [
  
      'org.gradle.api.plugins.JavaPlugin',
  
      'org.gradle.api.plugins.ScalaPlugin',
  
      'jp.leafytree.gradle.AndroidScalaPlugin'
  
    ]
  
    void apply(Gradle gradle) {
  
      def added = false
  
      gradle.allprojects { project ->
  
        project.with {
  
          if (parent == null) {
  
            buildscript {
  
          repositories {
  
            mavenLocal()
  
            mavenCentral()
  
                jcenter()
  
              }
  
          //if using snapshot, change rootProject.ensime.serverVersion to a snapshot
  
          //update this property to the lated ensime-gradle version
  
              dependencies {
  
            classpath 'net.coacoas.gradle:ensime-gradle:0.3.0-SNAPSHOT'
  
          }
  
            }
  
          }
  
          plugins.whenPluginAdded { plugin ->
  
            if (!added && supportedPlugins.contains(plugin.class.name)) {
  
              rootProject.apply plugin: 'org.ensime.gradle'
  
          //update the server version to the latest supported by the ensime-gradle plugin
  
          rootProject.ensime.serverVersion = "2.0.0-SNAPSHOT"
  
              added = true
  
            }
  
          }
  
        }
  
      }
  
    }
  
  }
  

• use

  gradle ensime