How to display classpath used for run task?

Question

How can the classpath used for run task be displayed under SBT 0.13?

I have found some info here https://groups.google.com/forum/#!msg/simple-build-tool/0rhVRPnjyZU/DOYAd14gh1wJ:

I was dumping my classpaths as a way to troubleshoot my build recently and maybe this task can help you too:

lazy val printClasspath = task {   this.runClasspath.getPaths.foreach(println);   None } 

runClasspath is a PathFinder [1] instance and you can interrogate it even further. I guess building a ':'-separated list of those paths will be easy.

I don't understand where and how I should use this tip. Please advise.

Answer 1

If I type this in the sbt shell:

inspect run 

I see, among other output:

[info] Dependencies: [info]  runtime:fullClasspath 

So then if I type:

show runtime:fullClasspath 

I get output like:

 List(    Attributed(/Users/tisue/Dropbox/repos/euler/target/scala-2.10/classes),    Attributed(/Users/tisue/.sbt/boot/scala-2.10.3/lib/scala-library.jar)) 

Which is probably what you were looking for?

You can also get it in a colon-separated form suitable for use with java -classpath on the command line:

export runtime:fullClasspath 

which prints e.g.:

/Users/tisue/Dropbox/repos/euler/target/scala-2.10/classes:/Users/tisue/.sbt/boot/scala-2.10.3/lib/scala-library.jar 

Answer 2

tl;dr Use last run or write a custom task.

last run

With last run you should be presented with the entire classpath:

[info] Running main.Main [debug] Waiting for threads to exit or System.exit to be called. [debug]   Classpath: [debug]     /Users/jacek/work/ingrifo/dictionary-spray/target/scala-2.11/classes [debug]     /Users/jacek/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.11.4.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-can_2.11/bundles/spray-can_2.11-1.3.2.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-io_2.11/bundles/spray-io_2.11-1.3.2.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-util_2.11/bundles/spray-util_2.11-1.3.2.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-http_2.11/bundles/spray-http_2.11-1.3.2.jar [debug]     /Users/jacek/.ivy2/cache/org.parboiled/parboiled-scala_2.11/bundles/parboiled-scala_2.11-1.1.6.jar [debug]     /Users/jacek/.ivy2/cache/org.parboiled/parboiled-core/bundles/parboiled-core-1.1.6.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-routing_2.11/bundles/spray-routing_2.11-1.3.2.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-httpx_2.11/bundles/spray-httpx_2.11-1.3.2.jar [debug]     /Users/jacek/.ivy2/cache/org.scala-lang.modules/scala-xml_2.11/bundles/scala-xml_2.11-1.0.2.jar [debug]     /Users/jacek/.ivy2/cache/org.jvnet.mimepull/mimepull/jars/mimepull-1.9.4.jar [debug]     /Users/jacek/.ivy2/cache/com.chuusai/shapeless_2.11/jars/shapeless_2.11-1.2.4.jar [debug]     /Users/jacek/.ivy2/cache/io.spray/spray-json_2.11/bundles/spray-json_2.11-1.3.1.jar [debug]     /Users/jacek/.ivy2/cache/com.typesafe.akka/akka-actor_2.11/jars/akka-actor_2.11-2.3.6.jar [debug]     /Users/jacek/.ivy2/cache/com.typesafe/config/bundles/config-1.2.1.jar [debug] Waiting for thread run-main-0 to terminate. [debug]     Thread run-main-0 exited. [debug] Waiting for thread default-akka.actor.default-dispatcher-4 to terminate. 

Custom task to dump CLASSPATH

If you need to see what the run task depends on, use inspect.

[fullclasspath]> inspect run [info] Input task: Unit [info] Description: [info]  Runs a main class, passing along arguments provided on the command line. [info] Provided by: [info]  {file:/Users/jacek/sandbox/so/fullClasspath/}fullclasspath/compile:run [info] Defined at: [info]  (sbt.Defaults) Defaults.scala:704 [info] Dependencies: [info]  compile:run::streams [info]  runtime:fullClasspath [info]  compile:run::runner [info]  compile:run::mainClass [info] Delegates: [info]  compile:run [info]  *:run [info]  {.}/compile:run [info]  {.}/*:run [info]  */compile:run [info]  */*:run [info] Related: [info]  test:run 

In Dependencies there's the runtime:fullClasspath setting which means that run depends on its value.

According to SBT help, fullClasspath is...

[fullclasspath]> help fullClasspath The exported classpath, consisting of build products and unmanaged and managed, internal and external dependencies. 

You simply need to parse the value of the runtime:fullClasspath setting.

[fullclasspath]> show runtime:fullClasspath [info] Updating {file:/Users/jacek/sandbox/so/fullClasspath/}fullclasspath... [info] Resolving org.fusesource.jansi#jansi;1.4 ... [info] Done updating. [info] List(Attributed(/Users/jacek/sandbox/so/fullClasspath/target/scala-2.10/classes), Attributed(/Users/jacek/.sbt/boot/scala-2.10.3/lib/scala-library.jar)) [success] Total time: 0 s, completed Feb 13, 2014 1:27:38 AM 

To have a more parsable output, use the following task that reads fullClasspath as defined for the runtime scope (Runtime in Scala/SBT code):

lazy val printClasspath = taskKey[Unit]("Dump classpath")  printClasspath := {   (fullClasspath in Runtime value) foreach {     e => println(e.data)   } } 

Unfortunatelly, the Runtime configuration is hardcoded and think an input task to accept a configuration would make it so much better.