Today I ran the refresh.xml from the udig libs plugin again to get back in sync with the current development. And I got an error about some ant task that can't be executed... ugh, it is not the first time.... wont be the last. Since my mind does not want to remember and this fools me every time, this time I document it. :)
What happens is that to execute ant tasks, the maven-ant-tasks package is used, which the uDig community holds inside the code trunk in:
So we are usually fine, the only thing is that from time to time, the jar: maven-ant-tasks-2.1.0.jar, currently at version 2.1.0 is updated and eclipse doesn't know were to find it any more.
Well, here is how to set it: preferences-> ant -> runtime
simply check that your path is set to a jar that really exists. If not, remove and add the existing jar (add external jar).