What could make Jasper Reports slower in a built RCP client versus a client started from Eclipse?

Question

I have an RCP application which is built with Tycho / Maven. The build uses both poms and manifests, in other words it really isn't pom first or manifest first.

I upgraded the Eclipse RCP Target Platform from 4.24 to 4.32.

Afterwards I noticed that in a Tycho built client, Pdf report generation with Jasper Reports took 2 - 3 times longer than before.

Jasper reports works closely with the JDT to compile reports.

I have tried all of this

• ensured context class loading was not a problem
• disabled lazy loading of the JDT plugins
• made sure the plugins were exported unzipped / exploded using Eclipse-BundleShape: dir
• upgraded JasperReports, DynamicJasper and JDT
• ensured that JDT was truly being used in Eclipse and in the built client with a profiler

After profiling the clients running from eclipse and the mvn built one from the command line, the bottleneck is clear : ClassLoader#getResourceAsStream.

In both profiling sessions, I have the identical invocation count, but from eclipse 28k invocations requires 2 seconds and the 28k invocations require 277 seconds on a built client.

Eclipse Client

Mvn / Tycho Client

Does anyone know why there is such a big difference in terms of clock time for resource loading?

Does anyone have any ideas what I can look into? The only way I see forward is ensuring the build is pom or manifest first so that I can ensure that a built client behaves in the same way as a client started from eclipse.