Increase memory in sbt-assembly

Question

Is there a way to increase the memory during assembly (the plugin)? I notice that adding more memory to sbt through SBT_OPTS does't really help. I suspect that assembly is forking a separate JVM that doesn't inherit the JVM configurations from sbt.

Here is the error:

java.util.concurrent.ExecutionException: java.lang.OutOfMemoryError: Java heap space

Here is what I tried without much luck:

javaOptions in assembly += "-Xmx2g"

Answer 1

I suspect that assembly is forking a separate JVM that doesn't inherit the JVM configurations from sbt.

I'm the author of sbt-assembly. assembly does not fork a separate JVM. You can see the code here and check - https://github.com/sbt/sbt-assembly/blob/0.13.0/src/main/scala/sbtassembly/Assembly.scala#L239-L246