How do I add a jar to SBT's classpath?

Question

I have a Java Play project and I added Snake Yaml to my class path.

libraryDependencies ++= Seq("org.yaml" % "snakeyaml" % "1.16")

This works great, my app can import org.yaml .

However, SBT cannot import org.yaml . It does not have access to libraryDependencies for some reason.

If I add import org.yaml.snakeyaml.Yaml to project/commons.scala , I get an error when I compile with activator compile .

[error] <path to project>/project/commons.scala:2: object yaml is not a member of package org
[error] import org.yaml.snakeyaml.Yaml
[error]            ^
[error] one error found
[error] (compile:compileIncremental) Compilation failed

How do I get make jars accessible within SBT?

Answer 1

Adding a dependency X to the source code of the project is not the same as adding a dependency X to your build code (a dependency to be used inside build.sbt , project/*.scala , etc.)

If that is what you are trying to do then you need to add the library dependency inside your project folder.

For example, just add libraryDependencies ++= Seq("org.yaml" % "snakeyaml" % "1.16") inside project/build.sbt (in contrast to adding in the normal ./build.sbt file).

Minimal project that showcase this

Structure:

.
├── build.sbt
└── project
    └── build.sbt

build.sbt

import org.yaml.snakeyaml.Yaml

name := "hello"

project/build.sbt

libraryDependencies ++= Seq("org.yaml" % "snakeyaml" % "1.16")