Typing `${folder_prompt}` in `working-dir` crashes the IDE

[kapexx]

Using the Eclipse variable ${folder_prompt} (which should open a dialog and prompt the user to choose a folder) in working-dir crashes the Eclipse IDE on Windows. As soon as you enter the variable in the editor, even before saving the file, Eclipse gets unresponsive and the process has to be killed. One time I noticed that the file chooser dialog popped up for a split second after entering the variable. My guess is that the variable is evaluated immediately after typing instead of when running the launch configuration. There's nothing logged about the crash in the Eclipse log. The variable works as expected in e.g. vm-arguments.