Apache Bigtop debugging changing do-component-build

When debugging Apache Bigtop I need to change do-component-build for one of the Bigtop components.

When running make rpm and you need to make a change in do-component-build for debugging, you cannot directly modify do-component-build and expect the build process to pick it up.

The make rpm process uses the rpmbuild command which operates on a rpm flle. The do-component-build script is embedded in the rpm file.

In my case I was getting pig-0.10 errors:

/home/dc/bigtop-0.5.0/build/pig/rpm/BUILD/pig-0.10.0/build.xml:540: java.lang.NullPointerException


This error is so generic and there aren't enough people using bigtop-0.5.0 to post blog fixes to help.

To modify the do-component-build, you have to exteract the src rpm, , modify do-component-build then re-rpm the changes into the src rpm.