Well, I guess the problem may be on a different level. When I launch `ftmulti` from the XQuartz-provided terminal (xterm), then it launches correctly (with the GUI). But if I launch it from within the regular "text" Terminal or iTerm apps, then I get the error. Same with `ftview` etc.
cannot open X11 display
could not allocate display surface
error = 0x0002
(The error is sometimes 0x0000 and sometimes 0x0002).
But the weird thing is that this used to work, 100%, just a few weeks ago. I did pull the new FreeType and built it, and then I rebuilt the ft2demos tools.
So this has to have something to do with the way FreeType has been built.