ID 163031 - "modalSession has been exited prematurely - check for a reentrant call to endModalSession:" error in terminal

Problem summary

I've only started seeing these Terminal errors since upgrading to OS X Mavericks in Breakaway 1.0dev. r82417.

Related Qt Support query on this:

http://qt-project.org/forums/viewthread/34118

Steps to reproduce

-Launch Breakaway from the Terminal
-Close the startup dialog (or raise a new modal dialog)

Result: error output in the Terminal:

2013-11-26 16:25:17.339 Breakaway1.0dev[19601:507] modalSession has been exited prematurely - check for a reentrant call to endModalSession: