What does xelatex error code Error 6 mean? Why will graphic not typeset correctly?

What does xelatex error code Error 6 mean? Why will graphic not typeset
correctly?

I cannot typeset a document with pictures (except pdf formatted pics). I
switched from MacTeX to MacPorts TexLive (installing with sudo port
install texlive*). I did this because I didn't want to mess with ensuring
Biber and Biblatex corresponded (like I used to have to do with MacTex.
Maybe this is no longer the case?)
The following is a simple document with a picture of a cardinal I
downloaded from here.
\documentclass[12pt]{article}
\usepackage{fontspec}
\usepackage{graphicx}
\DeclareGraphicsExtensions{.pdf,.png,.jpg,.jpeg}
%\graphicspath{{./main_images/}}
\begin{document}
\begin{figure}
\includegraphics[width=3cm]{cardinal.jpg}
\caption{Cardinal}
\end{figure}
\end{document}
This is the log:
This is XeTeX, Version 3.1415926-2.5-0.9999.3 (TeX Live 2013/MacPorts 2013_2)
restricted \write18 enabled.
entering extended mode
(./test.tex
LaTeX2e <2011/06/27>
Babel <3.9f> and hyphenation patterns for 87 languages loaded.
(/opt/local/share/texmf-texlive/tex/latex/base/article.cls
Document Class: article 2007/10/19 v1.4h Standard LaTeX document class
(/opt/local/share/texmf-texlive/tex/latex/base/size12.clo))
(/opt/local/share/texmf-texlive/tex/latex/fontspec/fontspec.sty
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/expl3.sty
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3names.sty
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3bootstrap.sty))
(/opt/local/share/texmf-texlive/tex/latex/etex-pkg/etex.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3basics.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3expan.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3tl.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3seq.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3int.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3quark.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3prg.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3clist.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3token.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3prop.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3msg.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3file.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3skip.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3keys.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3fp.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3box.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3coffins.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3color.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3luatex.sty)
(/opt/local/share/texmf-texlive/tex/latex/l3kernel/l3candidates.sty)
(/opt/local/share/texmf-texlive/tex/generic/oberdiek/ifpdf.sty))
(/opt/local/share/texmf-texlive/tex/latex/l3packages/xparse/xparse.sty)
(/opt/local/share/texmf-texlive/tex/latex/fontspec/fontspec-patches.sty
(/opt/local/share/texmf-texlive/tex/latex/base/fixltx2e.sty)
*************************************************
* LaTeX warning: "xparse/redefine-command"
*
* Redefining document command \oldstylenums with arg. spec. 'm' on line 128.
*************************************************
) (/opt/local/share/texmf-texlive/tex/latex/fontspec/fontspec-xetex.sty
(/opt/local/share/texmf-texlive/tex/latex/base/fontenc.sty
(/opt/local/share/texmf-texlive/tex/latex/euenc/eu1enc.def)
(/opt/local/share/texmf-texlive/tex/latex/euenc/eu1lmr.fd))
(/opt/local/share/texmf-texlive/tex/xelatex/xunicode/xunicode.sty
(/opt/local/share/texmf-texlive/tex/latex/tipa/t3enc.def
(/opt/local/share/texmf-texlive/tex/latex/euenc/eu1lmss.fd))
(/opt/local/share/texmf-texlive/tex/latex/graphics/graphicx.sty
(/opt/local/share/texmf-texlive/tex/latex/graphics/keyval.sty)
(/opt/local/share/texmf-texlive/tex/latex/graphics/graphics.sty
(/opt/local/share/texmf-texlive/tex/latex/graphics/trig.sty)
(/opt/local/share/texmf-texlive/tex/latex/latexconfig/graphics.cfg)
(/opt/local/share/texmf-texlive/tex/xelatex/xetex-def/xetex.def))))
(/opt/local/share/texmf-texlive/tex/latex/fontspec/fontspec.cfg)))
No file test.aux.
(/opt/local/share/texmf-texlive/tex/latex/tipa/t3cmr.fd)
<use "cardinal.jpg" > [1] (./test.aux) )
Error 6 (driver return code) generating output;
file test.pdf may not be valid.
SyncTeX written on test.synctex.gz.
Transcript written on test.log.