When attempting to build large modules (many Action Blocks within a Procedure Step), getting error in the Gen Build Tool of:
java.lang.OutOfMemoryError: Java heap space
Release : 8.6
Component : CA Gen Run Time, Distributed, BuildTool
Within the Gen Build Tool under the 'Tools' menu item select 'Profile Manager' and within the 'Java' tab, change the token OPT.JAVAFLAGS' value to something higher.
For example: Change this token value From: -Xmx256m To: -Xmx512m or higher and retry the build process.
In addition, if generating the module(s) (Procedure Step and called Action Blocks) with trace, may want to try the generation and subsequent build without trace as well.