If I open two Java projects in Eclipse which depend on each other, I have to add dependencies between these two projects in the Build Path (Properties -> Java build path). This works fine for one way, but why doesn't allow Eclipse to set the dependencies vice versa? The following error message occurs:

A cycle was detected in the build path of project 'A'

and

A cycle was detected in the build path of project 'B'

I know what's causing this error but i wonder why exactly this isn't allowed. Thanks.