Not a great start upgrading an app from g3 to g4, after 7 minutes of whirring fans and my causing me some concern with the noise and heat, I get back

Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded
	at org.grails.compiler.ValidateableTypeCheckingExtension$_run_closure5.doCall(ValidateableTypeCheckingExtension.groovy:61)

This is running in IntelliJ dev mode, Java 8 - with Xmx set to 1500.