Adding a JAR to a Grails project

When you find yourself working with an old Grails 2 project and you need to experiment with changes to one of its the dependencies without having to publish a snapshot version to an artifact repo, you can always drop the .jar into the lib folder and you are good to go. If you do not have a .pom file associated with the jar, attempting to use the local maven repo (.m2 folder) would result in the error below:

Resolve error obtaining dependencies: Failed to read artifact descriptor for com.amuponda:foo:jar:1.0.0-SNAPSHOT (Use --stacktrace to see the full trace)
Error |

With Grails 3 the lib directory was deprecated so the above approach will not work. You explicitly need to tell gradle to use it to resolve dependencies:

dependencies {
    ...
    compile fileTree(dir: './lib', include: \['\*.jar'\])
    ...
}