XV/GIMP/etc: Can't open display

[Ryan Schmidt]

On Jan 28, 2022, at 15:34, Dave Horsfall wrote:
> 
>    mackie:~ dave$ echo $DISPLAY
> 
>    mackie:~ dave$ 
> 
> Is this something I forgot to do during the upgrade?  I set $DISPLAY to 
> ":0" (an old Unix trick) to no effect,

Setting DISPLAY to :0 is correct on Mac OS X 10.4.x and earlier, but is incorrect on Mac OS X 10.5 and later and will cause problems.

On 10.5 and later, the X server (either the xorg-server port or the standalone XQuartz package) will set DISPLAY to the correct value for you when it has been properly installed and set up.