1. Inspect the build

Inspect the build 

Show or search help for a command, task, or setting 

The help command is used to show available commands and search the help for commands, tasks, or settings. If run without arguments, help lists the available commands.

> help

  help                         Displays this help message or prints detailed help on 
                                  requested commands (run 'help <command>').
  about                        Displays basic information about sbt and the build.
  reload                       (Re)loads the project in the current directory

> help compile

If the argument passed to help is the name of an existing command, setting or task, the help for that entity is displayed. Otherwise, the argument is interpreted as a regular expression that is used to search the help of all commands, settings and tasks.

The tasks command is like help, but operates only on tasks. Similarly, the settings command only operates on settings.

See also help help, help tasks, and help settings.

List available tasks 

The tasks command, without arguments, lists the most commonly used tasks. It can take a regular expression to search task names and descriptions. The verbosity can be increased to show or search less commonly used tasks. See help tasks for details.

The settings command, without arguments, lists the most commonly used settings. It can take a regular expression to search setting names and descriptions. The verbosity can be increased to show or search less commonly used settings. See help settings for details.

List available settings 

The inspect command displays several pieces of information about a given setting or task, including the dependencies of a task/setting as well as the tasks/settings that depend on the it. For example,

> inspect Test/compile
[info] Dependencies:
[info]  Test / manipulateBytecode
[info]  Test / enableBinaryCompileAnalysis
[info]  Test / compileIncSetup
[info] Reverse dependencies:
[info]  Test / products
[info]  Test / discoveredMainClasses
[info]  Test / printWarnings
[info]  Test / definedTestNames
[info]  Test / definedTests

See the Inspecting Settings page for details.

Display tree of setting/task dependencies 

In addition to displaying immediate forward and reverse dependencies as described in the previous section, the inspect command can display the full dependency tree for a task or setting. For example,

> inspect tree clean
[info] clean = Task[Unit]
[info]   +-clean / streams = Task[sbt.std.TaskStreams[sbt.internal.util.Init$ScopedKey[_ <: Any]]]
[info]   | +-Global / streamsManager = Task[sbt.std.Streams[sbt.internal.util.Init$ScopedKey[_ <: Any]]]
[info]   | 
[info]   +-cleanFiles = Task[scala.collection.Seq[java.io.File]]
[info]   | +-cleanKeepFiles = Vector(<project>/target/.history)
[info]   | | +-history = Some(<project>/target/.history)
[info]   | |   +-target = target
[info]   | |     +-baseDirectory = 

For each task, inspect tree show the type of the value generated by the task. For a setting, the toString of the setting is displayed. See the Inspecting Settings page for details on the inspect command.

Display the description and type of a setting or task 

While the help, settings, and tasks commands display a description of a task, the inspect command also shows the type of a setting or task and the value of a setting. For example:

> inspect update
[info] Task: sbt.librarymanagement.UpdateReport
[info] Description:
[info]  Resolves and optionally retrieves dependencies, producing a report.
> inspect scalaVersion
[info] Setting: java.lang.String = 2.12.6
[info] Description:
[info]  The version of Scala used for building.

See the Inspecting Settings page for details.

Display the delegation chain of a setting or task 

See the Inspecting Settings page for details.

Display related settings or tasks 

The inspect command can help find scopes where a setting or task is defined. The following example shows that different options may be specified to the Scala for testing and API documentation generation.

> inspect scalacOptions
[info] Related:
[info]  Compile / scalacOptions
[info]  Global / scalacOptions
[info]  Test / scalacOptions

See the Inspecting Settings page for details.

Show the list of projects and builds 

The projects command displays the currently loaded projects. The projects are grouped by their enclosing build and the current project is indicated by an asterisk. For example,

> projects
[info] In file:/home/user/demo/
[info]   * parent
[info]     sub
[info] In file:/home/user/dep/
[info]     sample

Show the current session (temporary) settings 

session list displays the settings that have been added at the command line for the current project. For example,

> session list
  1. maxErrors := 5
  2. scalacOptions += "-explaintypes"

session list-all displays the settings added for all projects. For details, see help session.

Show basic information about sbt and the current build 

> about
[info] This is sbt 1.1.5
[info] The current project is {file:~/code/sbt.github.com/}default
[info] The current project is built against Scala 2.12.6
[info] Available Plugins: sbt.plugins.IvyPlugin, sbt.plugins.JvmPlugin, sbt.plugins.CorePlugin, sbt.plugins.JUnitXmlReportPlugin, sbt.plugins.Giter8TemplatePlugin
[info] sbt, sbt plugins, and build definitions are using Scala 2.12.6

Show the value of a setting 

The inspect command shows the value of a setting as part of its output, but the show command is dedicated to this job. It shows the output of the setting provided as an argument. For example,

> show organization
[info] com.github.sbt 

The show command also works for tasks, described next.

Show the result of executing a task 

> show update
... <output of update> ...
[info] Update report:
[info]  Resolve time: 122 ms, Download time: 5 ms, Download size: 0 bytes
[info]  compile:
[info]      org.scala-lang:scala-library:
[info]              - 2.12.6
[info] ...

The show command will execute the task provided as an argument and then print the result. Note that this is different from the behavior of the inspect command (described in other sections), which does not execute a task and thus can only display its type and not its generated value.

> show compile:dependencyClasspath
[info] ArrayBuffer(Attributed(/Users/foo/.sbt/boot/scala-2.12.6/lib/scala-library.jar))

Show the classpath used for compilation or testing 

For the test classpath,

> show Test/dependencyClasspath
[info] List(Attributed(/Users/foo/code/sbt.github.com/target/scala-2.12/classes), Attributed(~/.sbt/boot/scala-2.12.6/lib/scala-library.jar), Attributed(/Users/foo/.ivy2/cache/junit/junit/jars/junit-4.8.2.jar))

Show the main classes detected in a project 

sbt detects the classes with public, static main methods for use by the run method and to tab-complete the runMain method. The discoveredMainClasses task does this discovery and provides as its result the list of class names. For example, the following shows the main classes discovered in the main sources:

> show compile:discoveredMainClasses
... <runs compile if out of date> ...
[info] List(org.example.Main)

Show the test classes detected in a project 

sbt detects tests according to fingerprints provided by test frameworks. The definedTestNames task provides as its result the list of test names detected in this way. For example,

> show Test/definedTestNames
... < runs test:compile if out of date > ...
[info] List(org.example.TestA, org.example.TestB)