Installing

[jamesray1]

Is it sufficient to just add ocgx2.sty to the same directory as the .tex file, for most intents and purposes?

[jamesray1]

Unfortunately it seems that it isn't.

After adding the file I get another Travis build error:
https://travis-ci.org/ethereum/yellowpaper/builds/335012552?utm_source=github_status&utm_medium=notification

$ ./build.sh
This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Debian)
...
(./ocgx2.sty
(/usr/share/texlive/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/expl3.sty
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3names.sty
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty))
(/usr/share/texlive/texmf-dist/tex/latex/etex-pkg/etex.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3basics.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3expan.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3tl.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3seq.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3int.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3quark.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3prg.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3clist.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3token.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3prop.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3msg.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3file.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3skip.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3keys.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3fp.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3box.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3coffins.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3color.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3luatex.sty)
(/usr/share/texlive/texmf-dist/tex/latex/l3kernel/l3candidates.sty)))
(/usr/share/texlive/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty)
! Undefined control sequence.
l.151 \sys_if_engine_xetex:T
                            {
!  ==> Fatal error occurred, no output PDF file produced!
Transcript written on Paper.log.

[jamesray1]

Ah I see that ocgx2.sty has \RequirePackage{ocgbase}.

[jamesray1]

After adding ocgx2.sty and ocgbase.sty, I'm still getting an error:

! Undefined control sequence.
l.151 \sys_if_engine_xetex:T
                            {
!  ==> Fatal error occurred, no output PDF file produced!

[jamesray1]

Related: https://stackoverflow.com/questions/37156696/undefined-control-sequence-error-while-converting-from-markdown-to-pdf-with-pand#37207843.

[jamesray1]

Using texlive texlive-latex3 and texlive-latex-extra on Trusty.

[jamesray1]

It's using pdfTeX as shown in this build output.

[jamesray1]

I found this:

latex3/latex3@d230e78#diff-ec781ddf43396a57dd5e8997241927c7R288

There are other results for \sys_if_engine_xetex:T on that page, but that one looks like it is the most relevant with the gset option.

This is the latest version:
https://github.com/latex3/latex3/blob/master/l3trial/l3benchmark/l3benchmark.dtx

There are 5 results for \sys_if_engine_xetex:T in that latest version, and https://github.com/latex3/latex3/blob/master/l3trial/l3benchmark/l3benchmark.dtx#L301 uses gset.

I don't know why you're using \bool_gset_true:N\g_ocgxii_dvipdfmx_bool, nor do I understand lines 301–312, and don't have the time to learn at the moment, so I'll give you some time to figure out how to solve this.

[jamesray1]

In your file:

%process package options
\ProcessKeysOptions{ocgx2}
\sys_if_engine_xetex:T{
  \bool_gset_true:N\g_ocgxii_dvipdfmx_bool
  %we use the period `.' from this downscaled font at the end of ocgcolorlinks,
  %preventing empty links from flooding the page with link color
  \font\g_ocgxii_lmroman_tl="[lmroman5-regular.otf]"~scaled~1
}

[jamesray1]

The same issue is here:
https://tex.stackexchange.com/questions/412790/how-to-install-the-ocgx2-package-which-is-not-available-on-https-packages-ubun
Here's a related, older issue:
https://tex.stackexchange.com/questions/392832/how-to-ensure-that-a-url-break-over-a-page-doesnt-add-a-tiny-url-box-in-the-hea

[agrahn]

Well, LaTeX packages may depend on other packages and even more, they may require a minimum version of such a dependency. Instead of using an old frozen or split up TeX distro as they are usually provided by Linux distributions such as Ubuntu (TL-2013, see above), it is much safer to download the current vanilla TeXLive distribution from CTAN and to install it into the $HOME directory. This spares you a lot of time and frustration trying to figure out manually the dependencies required. I did the same. From time to time I run the TL package manager (tlmgr update --all --self) to update installed packages and get new ones as they appear on CTAN. Most package authors, and this sounds quite natural to me, test their developments against the current package versions, available on CTAN/TeXLive, if they depend on those.