Maven compilation dies with "Killed"

Question

I am running a Maven2 compile of a large Java project on a linux virtual machine
Compilation is failing with the following error "compiled with -X for debugging"

[DEBUG] Source roots:
[DEBUG] /home/{...}/src/main/java
[DEBUG] /home/{...}/target/generated-sources/meta
[INFO] Compiling 1377 source files to /home/{...}
Killed
(and I go back to bash prompt immediately)

I figure this could be:

• A linux thing (I checked that my ulimit -Hn is okay, 10000)
• A VM thing (this in on an amazon EC2 ubuntu instance)
• A maven / java thing (Never seen this kind of death, usually just out of memory errors and the like)

Any thoughts to narrow down the culprit?