Out of memory error

[larrykollar]

I was able to update in mid-March. Now I'm getting out of memory errors:

larry$ s3_website push
[info] Downloading https://github.com/laurilehmijoki/s3_website/releases/download/v3.4.0/s3_website.jar into /var/folders/fq/p1v8pqfd7lx87mxqpvmxltxm0000gq/T//s3_website-3.4.0.jar
[info] Deploying /Users/larry/Documents/blog/_site/* to www.larrykollar.com
Exception in thread "pool-1-thread-9" java.lang.OutOfMemoryError: Java heap space
	at scala.collection.mutable.ListBuffer.$plus$eq(ListBuffer.scala:174)
	at scala.collection.mutable.ListBuffer.$plus$eq(ListBuffer.scala:45)
	at scala.collection.generic.Growable$class.loop$1(Growable.scala:53)
	at scala.collection.generic.Growable$class.$plus$plus$eq(Growable.scala:57)
	at scala.collection.mutable.ListBuffer.$plus$plus$eq(ListBuffer.scala:183)
	at scala.collection.mutable.ListBuffer.$plus$plus$eq(ListBuffer.scala:45)
	at scala.collection.TraversableLike$class.$plus$plus(TraversableLike.scala:157)
	at scala.collection.immutable.List.$plus$plus(List.scala:196)
	at s3.website.S3$$anonfun$resolveS3Files$2.apply(S3.scala:140)
	at s3.website.S3$$anonfun$resolveS3Files$2.apply(S3.scala:132)
	at scala.concurrent.Future$$anonfun$flatMap$1.apply(Future.scala:251)
	at scala.concurrent.Future$$anonfun$flatMap$1.apply(Future.scala:249)
	at scala.concurrent.impl.CallbackRunnable.run(Promise.scala:32)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

This is happening on MacOSX 10.13.4. I'm not sure if a system update or a Java update is to blame here.

larry$ java -version
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)

Any thoughts? Thanks.