pagination.tex

\documentclass[landscape,a4paper]{article}
\usepackage{luacode}
\usepackage{pdfpages}

\begin{document}
\begin{luacode*}
  local options = [==[
    pages= -,
    nup = 2x2,
    width = 0.49\paperwidth,
    offset = 0.1cm 0cm,
    delta = 0.2cm 0.7cm
  ]==]

  local target = os.getenv('PAGINATION_TARGET') or 'main.pdf'

  if not target:match('%.pdf$') then
    target = target..'.pdf'
  end

  options = options:gsub('\n', '')

  tex.print(([==[\includepdf[%s]{%s}]==]):format(options, target))
\end{luacode*}
\end{document}