Buildsbt

Buildsbt is the sbt-based build configuration used for Scala projects. The term commonly refers to the build definitions written in the build.sbt file at the project root, together with related files in the project directory. The build tool sbt uses these definitions to manage project settings, dependencies, and the lifecycle of compilation and packaging. While build.sbt is the conventional entry point, larger builds may include additional settings in Scala files under the project directory.

Structure and files: The root contains build.sbt, with optional project/plugins.sbt for plugins. Additional settings can be declared in project/*.scala or other .sbt files. The build uses a DSL based on Scala to declare settings and tasks. Settings can be scoped to the entire build or to individual modules, and cross-building can be configured with ThisBuild or inThisBuild blocks.

Key concepts and syntax: Core keys include name, version, scalaVersion, and libraryDependencies. Other common keys are resolvers, scalacOptions, and crossScalaVersions. The syntax uses operators such as := for assignments, += and ++= for appending, and inThisBuild for global settings. An example build.sbt snippet shows how these keys are declared and combined to configure a project.

Example (text): name := "Example" version := "0.1.0" scalaVersion := "2.13.8" libraryDependencies += "org.typelevel" %% "cats-core" % "2.6.1"

Usage: Run sbt from the project root to enter an interactive session, then issue commands such as compile, test, run, package, publishLocal, or publish. sbt resolves dependencies from configured repositories like Maven Central and any custom resolvers. The build can be extended with plugins defined in project/plugins.sbt, which may add tasks, commands, or additional settings.

Origins and scope: sbt was developed to provide a fast, incremental build tool tailored to the Scala ecosystem, leveraging Ivy for dependency resolution and a plugin system for extensibility. Build definitions are portable across environments and are central to managing multi-project builds in Scala.