Description of problem:
Running

x,y=var('x, y')
plot3d((x^2)*y-x*y+x*y^3,(x,0,5),(y,0,5))

returns

Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.awt.HeadlessException: 
No X11 DISPLAY variable was set, but this program performed an operation
which requires it.
	at sun.awt.HeadlessToolkit.getScreenSize(HeadlessToolkit.java:284)
	at
org.openscience.jmol.app.jmolpanel.JmolPanel.<clinit>(JmolPanel.ja\
va:173)
/usr/lib64/python2.7/site-packages/sage/repl/rich_output/display_manager\
.py:570: RichReprWarning: Exception in _rich_repr_ while displaying
object: Jmol failed to create file
'/home/sage/.sage/temp/host/1582/dir_631amd/preview.png', see
'/home/sage/.sage/temp/host/1582/tmp_q2GQOi.txt' for details
  RichReprWarning,
Graphics3d Object


Version-Release number of selected component (if applicable):
sagemath-6.8-14.fc24.x86_64