I\'ve started using the UI Test features of Xcode 7, and when I run a test, I get the output from testing showing up in the content pane of the debugging area.
However,
Might not completely solve your issue: I was having a similar problem (and found your question!) and just found out that you can select which logging output is shown in the Debug Area:
Maybe, if you combine this with a cleverly inserted test breakpoint you might (partially) achieve what you were looking for ;-)