So, one of our developers was seeing some odd results in his Jenkins cobertura reports. The tests weren't changing, but the coverage numbers were fluctuating. Reviewing the logs, I found a common issue (shown below).

Results

Instead of typing up everything I tried over the last couple of days, i'll just put down basic notes :

• Maven : v 3.0.3 (and up)
• Cobertura Maven Plugin : 2.4 - fixes the issue
• Cobertura Maven Plugin : 2.3 - doesn't work (has issues shown in log above)
• Cobertura Maven Plugin : 2.51 - doesn't work (has classloader MavenReport issues)
• -Dcobertura.use.java.nio=false - Unnecessary (in my case)