Mac: Xcode 7.3 problem

[Vic Norton]

I’ve been using Octave graphics at least once a week on my iMac for quite some 
time (OS X 10.11.4, Octave, version 4.0.0, Gnuplot, version 5.0 patchlevel 3) 
with no problems until today. Today I installed Apple’s Xcode, version 7.3, 
along with Apple’s Command Line Tools (OS X 10.11) for Xcode, version 3.3, both 
of which came out Monday, March 21. These upgrades to Apple’s system have 
apparently doomed Octave graphics.

Here is a simple example:
  octave> clear all
  octave> x = 0 : 0.1 : 4;
  octave> plot(x, sin(x));
  ^C^CPress Control-C again to abort.
  ^Cpanic: Interrupt: 2 -- stopping myself...
  attempting to save variables to 'octave-workspace'...
  save to 'octave-workspace' complete
The control C’s are necessary to get back to the real world.

Does anyone know of a fix for this problem. I suppose I need to un-upgrade 
Xcode and Command line Tools and get back to the previous versions, but I’m not 
sure how to do this.

Any advice would be much appreciated.

Regards,

Vic