;; org-export.el
(require 'org)
(require 'python)
(python-shell-prompt-detect)
(setq org-src-preserve-indentation t
      org-src-fontify-natively t
      org-export-latex-listings t
 org-latex-listings 'listings
      org-latex-prefer-user-labels t
      org-confirm-babel-evaluate nil
      org-cite-export-processors nil
;     org-cite-export-processors '((beamer . biblatex)
;                                  (latex .  biblatex))
      org-cite-biblatex-options

"backend=biber,style=numeric,sorting=none,isbn=false,doi=false,url=true"
      ;; Make sure you have bibtex integrated in the production loop
      org-latex-pdf-process
        '("latexmk -bibtex -pdflatex='pdflatex --shell-escape
--interaction=nonstopmode' -pdf -f %f")
        org-babel-python-command (executable-find "python3"))
(add-to-list 'org-latex-packages-alist '("" "listings"))
(org-babel-do-load-languages  'org-babel-load-languages
                              '((python . t)
                                (shell . t)))

command:

emacs -Q -l export-beamer.el --batch flat.org --eval
'(org-beamer-export-to-pdf)'

error produced

File mode specification error: (error Invalid face box :line-width 1 :color
grey40)

Previous commit (a91185211924f65adf7c1376b7f2d710099a5903) produces the PDF
file


-- 
Fragen sind nicht da, um beantwortet zu werden,
Fragen sind da um gestellt zu werden
Georg Kreisler

Headaches with a Juju log:
unit-basic-16: 09:17:36 WARNING juju.worker.uniter.operation we should run
a leader-deposed hook here, but we can't yet