Coursier

2.0.0-RC6-20

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Overview

The CLI of coursier has a number of commands to deal with dependencies and artifacts:

See Installation for how to install the CLI of coursier.

This page succinctly describes each of these commands. More details about each them are then given in the dedicated documentation page of each command (see links on the left).

Available commands

resolve

resolve lists the transitive dependencies of one or more other dependencies. Use like

$ cs resolve io.circe::circe-generic:0.12.3
com.chuusai:shapeless_2.13:2.3.3:default
io.circe:circe-core_2.13:0.12.3:default
io.circe:circe-generic_2.13:0.12.3:default
io.circe:circe-numbers_2.13:0.12.3:default
org.scala-lang:scala-library:2.13.0:default
org.typelevel:cats-core_2.13:2.0.0:default
org.typelevel:cats-kernel_2.13:2.0.0:default
org.typelevel:cats-macros_2.13:2.0.0:default

Note that this only relies on metadata files (POMs in particular), and doesn't download any JAR.

resolve has more options, to print trees, find which dependency brings another one, etc. See the dedicated page for more details.

fetch

fetch fetches the JARs of one or more dependencies.

$ cs fetch io.circe::circe-generic:0.12.3
/path/to/coursier/cache/https/repo1.maven.org/maven2/io/circe/circe-generic_2.13/0.12.3/circe-generic_2.13-0.12.3.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/org/scala-lang/scala-library/2.13.0/scala-library-2.13.0.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/io/circe/circe-core_2.13/0.12.3/circe-core_2.13-0.12.3.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/com/chuusai/shapeless_2.13/2.3.3/shapeless_2.13-2.3.3.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/io/circe/circe-numbers_2.13/0.12.3/circe-numbers_2.13-0.12.3.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/org/typelevel/cats-core_2.13/2.0.0/cats-core_2.13-2.0.0.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/org/typelevel/cats-macros_2.13/2.0.0/cats-macros_2.13-2.0.0.jar
/path/to/coursier/cache/https/repo1.maven.org/maven2/org/typelevel/cats-kernel_2.13/2.0.0/cats-kernel_2.13-2.0.0.jar

fetch has more options, to join its output with the path separator, fetch source JARs, fetch javadoc, etc. See the dedicated page for more details.

launch

launch launches applications from one or more dependencies.

$ cs launch org.scalameta::scalafmt-cli:2.4.2 -- --help
scalafmt 2.4.2
Usage: scalafmt [options] [<file>...]

  -h, --help               prints this usage text
  -v, --version            print version
…

Arguments can be passed to the application after --.

launch has more options, to specify a main class, pass Java options, etc. See the dedicated page for more details.

bootstrap

bootstrap creates binary launchers from one or more dependencies.

$ cs bootstrap org.scalameta::scalafmt-cli:2.4.2 -o scalafmt
$ ./scalafmt --version
scalafmt 2.4.2

bootstrap can generate a variety of launchers, including native ones like GraalVM native images or Scala Native executables. See the dedicated page for more details.

install

The install command creates launchers for applications in the installation directory (~/.local/share/coursier/bin on Linux):

$ eval "$(cs install --env)" # add installation directory in PATH in the current session
$ cs install scalafmt
$ scalafmt --version
scalafmt 2.4.2

One can run cs install --setup to update profile files (Linux / macOS) or user environment variables (Windows), to add the installation directory to PATH.

See the dedicated page for more details.

java

The java command manages JVMs. For example, the following command

$ cs java --jvm 11 -version
openjdk version "11.0.6" 2020-01-14
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.6+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.6+10, mixed mode)

will automatically download the latest AdoptOpenJDK 11 (in the coursier cache), unpack it (in the managed JVM directory), and run it with -version.

It uses the index of jabba to know where to download JVM archives, and assumes AdoptOpenJDK if only a version is passed.

The java-home command prints the Java home of a JVM, like

$ cs java-home --jvm 9
~/Library/Caches/Coursier/jvm/adopt@1.9.0-0/Contents/Home

One can update profile files (Linux / macOS) or user environment variables (Windows) for a specific JVM with --setup, like

$ cs java --jvm openjdk:1.14 --setup

(This updates JAVA_HOME and PATH.)

You don't have to update these environment variables if you prefer not to. For example, one can just get a Java home with

$ cs java-home --jvm graalvm:20
~/Library/Caches/Coursier/jvm/graalvm@20.0.0/Contents/Home

or set environment variables only for the current session with

$ eval "$(cs java --env --jvm 11)"
$ java -version
openjdk version "11.0.6" 2020-01-14
OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.6+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.6+10, mixed mode)

These two commands only write things in the coursier cache, and the managed JVM directory, which is a cache too (both of these directories live under ~/.cache/coursier on Linux, ~/Library/Caches/Coursier on macOS).

The dedicated page gives more details about the java and java-home commands.

setup

setup ensures that:

  • a JVM is installed on your machine,
  • the installation directory of the install command is in your PATH,
  • the standard Scala applications are installed on your system.

setup is a "repackaging" of features of the java and install commands. One doesn't have to run setup for the other commands to work fine, it's just a convenience.

The features that setup wraps up are not tied to each other. You can rely on the java or java-home commands while managing applications with your preferred package manager. Or you can manage JVMs any other way while using the install command. setup only conveniently sets them up in one go, and it only sets up a JVM if it doesn't find one already installed.

See the dedicated page for more details about what the setup command does.

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