Findbugs failed when no history found

We have findbugs on a project and so far it was running happily with following configuration.

apply plugin: 'findbugs'
    findbugs {
        ignoreFailures = true

With last build it broke (bellow is report from debug). Before the last commit we did one other commit that was targeting findbugs issues and we got them all resolved.

OK, ignore it this please. It was actually compile error down to bad merge that got hidden behind all the findbugs failure messages