Recently I needed to use a Groovy Script that would make a JDBC connection to Redshift. I was running into the following errors:

java.lang.RuntimeException: Error grabbing Grapes -- [unresolved dependency: com.amazon.redshift#redshift-jdbc42;1.2.34.1058: not found]

My Grapes annotation looked like this:

@Grapes([@Grab(group='com.amazon.redshift', module='redshift-jdbc42', version='1.2.36.1060')])
@GrabConfig(systemClassLoader=true)

The root of the issue is that the repository for this is hosted at mulesoft not Maven. To Resolve simply add a @GrabResolver. The following Grapes annotations in my script resolved the issue:

@GrabResolver(name='mulesoft', root='https://repository.mulesoft.org/nexus/content/repositories/public/')
@GrabConfig(systemClassLoader=true)
@Grapes([@Grab(group='com.amazon.redshift', module='redshift-jdbc42', version='1.2.36.1060')])