[luatex] Undefined Control Sequence with attachfile package

[Jon Hood]

Attempting to run lualatex on the following results in an error. Am I
doing something wrong with the attachfile package? It says that it
supports luatex, and it works fine when I use pdflatex...

$ lualatex --version
This is LuaTeX, Version 1.0.4 (TeX Live 2017/Cygwin)

$ grep -A 1 ProvidesPackage
/usr/share/texmf-dist/tex/latex/attachfile/attachfile.sty
\ProvidesPackage{attachfile}
    [2016/09/18 v1.9 PDF 1.3+ file attachment]

$ cat mwe.tex
\documentclass{article}
\usepackage{attachfile}
\begin{document}
\attachfile[icon=Paperclip, mimetype=text/plain]{mwe.tex}
\end{document}

$ lualatex mwe
This is LuaTeX, Version 1.0.4 (TeX Live 2017/Cygwin)
 restricted system commands enabled.
(./mwe.tex
LaTeX2e <2017-04-15>
(using cache: /var/lib/texmf/luatex-cache/generic)
luaotfload | main : initialization completed in 0.141 seconds
Babel <3.10> and hyphenation patterns for 1 language(s) loaded.
(/usr/share/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/usr/share/texmf-dist/tex/latex/base/size10.clo(load luc: /var/lib/texmf/luate
x-cache/generic/fonts/otl/lmroman10-regular.luc)))
(/usr/share/texmf-dist/tex/latex/attachfile/attachfile.sty
(/usr/share/texmf-dist/tex/generic/oberdiek/ifpdf.sty)
(/usr/share/texmf-dist/tex/latex/graphics/keyval.sty)
(/usr/share/texmf-dist/tex/latex/tools/calc.sty)
(/usr/share/texmf-dist/tex/latex/graphics/color.sty
(/usr/share/texmf-dist/tex/latex/graphics-cfg/color.cfg)
(/usr/share/texmf-dist/tex/latex/graphics-def/luatex.def
(/usr/share/texmf-dist/tex/generic/oberdiek/infwarerr.sty)
(/usr/share/texmf-dist/tex/generic/oberdiek/ltxcmds.sty)))
(/usr/share/texmf-dist/tex/latex/hyperref/hyperref.sty
(/usr/share/texmf-dist/tex/generic/oberdiek/hobsub-hyperref.sty
(/usr/share/texmf-dist/tex/generic/oberdiek/hobsub-generic.sty
(/usr/share/texmf-dist/scripts/oberdiek/oberdiek.luatex.lua)))
(/usr/share/texmf-dist/tex/generic/ifxetex/ifxetex.sty)
(/usr/share/texmf-dist/tex/latex/oberdiek/auxhook.sty)
(/usr/share/texmf-dist/tex/latex/oberdiek/kvoptions.sty)
(/usr/share/texmf-dist/tex/latex/hyperref/pd1enc.def)
(/usr/share/texmf-dist/tex/latex/latexconfig/hyperref.cfg)
(/usr/share/texmf-dist/tex/latex/url/url.sty))

Package hyperref Message: Driver (autodetected): hluatex.

(/usr/share/texmf-dist/tex/latex/hyperref/hluatex.def
(/usr/share/texmf-dist/tex/latex/oberdiek/rerunfilecheck.sty))) (./mwe.aux)
(/usr/share/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
[Loading MPS to PDF converter (version 2006.09.02).]
) (/usr/share/texmf-dist/tex/latex/hyperref/nameref.sty
(/usr/share/texmf-dist/tex/generic/oberdiek/gettitlestring.sty)) (./mwe.out)
(./mwe.out)<<mwe.tex>>
! Undefined control sequence.
\atfi at set@appearance  ...x }}\immediate \pdfxform
                                                  \atfi at appearancebox \edef ...

l.4 ...icon=Paperclip, mimetype=text/plain]{mwe.tex}