[R-SIG-Mac] illegal operation on vignette("xkcd-intro"): pdf viewer perhaps?

[Tim Bates]

On R version: R version 3.4.2 (2017-09-28) (Platform: x86_64-apple-darwin15.6.0, MacOS: 10.13.1)

load library(xkcd), and then try and run the vignette:

vignette("xkcd-intro")

 *** caught illegal operation ***
address 0x7fff7429b5e2, cause 'illegal opcode'

Traceback:
 1: system2(pdfviewer, shQuote(out), wait = FALSE)
 2: print.vignette(x)
 3: function (x, ...) UseMethod("print")(x)

Possible actions...