No X11 DISPLAY variable was set on Mac

Question

I am running an application from terminal. It is expected to launch an Application specific debugger GUI which internally talks to GDB. I have tried {export DISPLAY=localhost:0.0} & {export DISPLAY=:0.0}. This doesn't work. On my linux machine I was able to run the application without the heck of setting DISPLAY.

No X11 DISPLAY variable was set, but this program performed an operation which requires it.
at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207)`
at java.awt.Window.<init>(Window.java:535)
at java.awt.Frame.<init>(Frame.java:420)
at javax.swing.JFrame.<init>(JFrame.java:224)
at charm.debug.ParDebug.main(ParDebug.java:2291)

Solution

Mac(s) don't run X11 by default (the core desktop environment on a Mac is also known as Quartz). You'll need to install (and run) an X server. Per Apple support

X11 is no longer included with OS X, but X11 server and client libraries for OS X are available from the XQuartz project.

XQuartz is available.