Ant and javadoc

I'm executing javadoc from an Ant script, using IDEA to run it.

It's failing to execute the javadoc, giving the following error:



The Ant file works OK when run outside IDEA - or even when run under the debugger!

I think it's something to do with not finding the javadoc exe - maybe IDEA is looking under a JRE instead of a JDK?

In http://www.intellij.net/tracker/idea/viewSCR?publicId=7085, the recommendation was to use a custom JDK in the Ant build file properties dialog. I tried this and it worked.

However, it would seem that using javadoc in IDEA doesn't work "out of the box". I think that it should...