Unable to load ox-pandoc

[KirmTwinty]

Since I customized org-export-backends through the M-x customize, command, I encounter the following error at startup:
Here is the code used to load ox-pandoc:

(use-package ox-pandoc
  :config 
  (with-eval-after-load 'ox
    (require 'ox-pandoc)))

and here is the error :

Debugger entered--Lisp error: (error "Cannot use unknown \"org\" back-end as a parent")
  signal(error ("Cannot use unknown \"org\" back-end as a parent"))
  error("Cannot use unknown \"%s\" back-end as a parent" org)
  org-export-register-backend(#s(org-export-backend :name pandoc :parent org :transcoders ((entity . org-pandoc-entity) (export-block . org-pandoc-export-block) (latex-environment . org-pandoc-latex-environ) (link . org-pandoc-link) (paragraph . org-pandoc-paragraph) (src-block . org-pandoc-src-block) (table . org-pandoc-table) (template . org-pandoc-template)) :options ((:pandoc-options "PANDOC_OPTIONS" nil nil space) (:pandoc-extensions "PANDOC_EXTENSIONS" nil nil space) (:pandoc-metadata "PANDOC_METADATA" nil nil space) (:pandoc-variables "PANDOC_VARIABLES" nil nil space) (:epub-chapter-level "EPUB_CHAPTER_LEVEL" nil nil t) (:epub-cover-image "EPUB_COVER" nil nil t) (:epub-stylesheet "EPUB_STYLESHEET" nil nil t) (:epub-embed-font "EPUB_EMBED_FONT" nil nil newline) (:epub-meta "EPUB_META" nil nil newline) (:epub-css "EPUB_CSS" nil nil newline) (:epub-rights "EPUB_RIGHTS" nil nil newline) (:bibliography "BIBLIOGRAPHY")) :filters nil :blocks nil :menu (112 "export via pandoc" ((52 "to html5 and open." org-pandoc-export-to-html5-and-open) (36 "as html5." org-pandoc-export-as-html5) (53 "to html5-pdf and open." org-pandoc-export-to-html5-pdf-and-open) (37 "to html5-pdf." org-pandoc-export-to-html5-pdf) (60 "to slideous and open." org-pandoc-export-to-slideous-and-open) (44 "as slideous." org-pandoc-export-as-slideous) (61 "to ms-pdf and open." org-pandoc-export-to-ms-pdf-and-open) (45 "to ms-pdf." org-pandoc-export-to-ms-pdf) (98 "to beamer-pdf and open." org-pandoc-export-to-beamer-pdf-and-open) (66 "to beamer-pdf." org-pandoc-export-to-beamer-pdf) (99 "to context-pdf and open." org-pandoc-export-to-context-pdf-and-open) (67 "to context-pdf." org-pandoc-export-to-context-pdf) (100 "to docbook5 and open." org-pandoc-export-to-docbook5-and-open) (68 "as docbook5." org-pandoc-export-as-docbook5) (101 "to epub3 and open." org-pandoc-export-to-epub3-and-open) (69 "to epub3." org-pandoc-export-to-epub3) (103 "to gfm and open." org-pandoc-export-to-gfm-and-open) (71 "as gfm." org-pandoc-export-as-gfm) (104 "to html4 and open." org-pandoc-export-to-html4-and-open) (72 "as html4." org-pandoc-export-as-html4) (105 "to icml and open." org-pandoc-export-to-icml-and-open) (73 "as icml." org-pandoc-export-as-icml) (106 "to json and open." org-pandoc-export-to-json-and-open) (74 "as json." org-pandoc-export-as-json) (108 "to latex-pdf and open." org-pandoc-export-to-latex-pdf-and-open) (76 "to latex-pdf." org-pandoc-export-to-latex-pdf) (109 "to man and open." org-pandoc-export-to-man-and-open) (77 "as man." org-pandoc-export-as-man) (110 "to native and open." org-pandoc-export-to-native-and-open) (78 "as native." org-pandoc-export-as-native) (111 "to odt and open." org-pandoc-export-to-odt-and-open) (79 "to odt." org-pandoc-export-to-odt) (112 "to pptx and open." org-pandoc-export-to-pptx-and-open) (80 "to pptx." org-pandoc-export-to-pptx) (114 "to rtf and open." org-pandoc-export-to-rtf-and-open) (82 "as rtf." org-pandoc-export-as-rtf) (117 "to dokuwiki and open." org-pandoc-export-to-dokuwiki-and-open) (85 "as dokuwiki." org-pandoc-export-as-dokuwiki) (118 "to revealjs and open." org-pandoc-export-to-revealjs-and-open) (86 "as revealjs." org-pandoc-export-as-revealjs) (119 "to mediawiki and open." org-pandoc-export-to-mediawiki-and-open) (87 "as mediawiki." org-pandoc-export-as-mediawiki) (120 "to docx and open." org-pandoc-export-to-docx-and-open) (88 "to docx." org-pandoc-export-to-docx) (121 "to slidy and open." org-pandoc-export-to-slidy-and-open) (89 "as slidy." org-pandoc-export-as-slidy) (122 "to dzslides and open." org-pandoc-export-to-dzslides-and-open) (90 "as dzslides." org-pandoc-export-as-dzslides)))))
  org-export-define-derived-backend(pandoc org :translate-alist ((entity . org-pandoc-entity) (export-block . org-pandoc-export-block) (latex-environment . org-pandoc-latex-environ) (link . org-pandoc-link) (paragraph . org-pandoc-paragraph) (src-block . org-pandoc-src-block) (table . org-pandoc-table) (template . org-pandoc-template)) :menu-entry (112 "export via pandoc" ((52 "to html5 and open." org-pandoc-export-to-html5-and-open) (36 "as html5." org-pandoc-export-as-html5) (53 "to html5-pdf and open." org-pandoc-export-to-html5-pdf-and-open) (37 "to html5-pdf." org-pandoc-export-to-html5-pdf) (60 "to slideous and open." org-pandoc-export-to-slideous-and-open) (44 "as slideous." org-pandoc-export-as-slideous) (61 "to ms-pdf and open." org-pandoc-export-to-ms-pdf-and-open) (45 "to ms-pdf." org-pandoc-export-to-ms-pdf) (98 "to beamer-pdf and open." org-pandoc-export-to-beamer-pdf-and-open) (66 "to beamer-pdf." org-pandoc-export-to-beamer-pdf) (99 "to context-pdf and open." org-pandoc-export-to-context-pdf-and-open) (67 "to context-pdf." org-pandoc-export-to-context-pdf) (100 "to docbook5 and open." org-pandoc-export-to-docbook5-and-open) (68 "as docbook5." org-pandoc-export-as-docbook5) (101 "to epub3 and open." org-pandoc-export-to-epub3-and-open) (69 "to epub3." org-pandoc-export-to-epub3) (103 "to gfm and open." org-pandoc-export-to-gfm-and-open) (71 "as gfm." org-pandoc-export-as-gfm) (104 "to html4 and open." org-pandoc-export-to-html4-and-open) (72 "as html4." org-pandoc-export-as-html4) (105 "to icml and open." org-pandoc-export-to-icml-and-open) (73 "as icml." org-pandoc-export-as-icml) (106 "to json and open." org-pandoc-export-to-json-and-open) (74 "as json." org-pandoc-export-as-json) (108 "to latex-pdf and open." org-pandoc-export-to-latex-pdf-and-open) (76 "to latex-pdf." org-pandoc-export-to-latex-pdf) (109 "to man and open." org-pandoc-export-to-man-and-open) (77 "as man." org-pandoc-export-as-man) (110 "to native and open." org-pandoc-export-to-native-and-open) (78 "as native." org-pandoc-export-as-native) (111 "to odt and open." org-pandoc-export-to-odt-and-open) (79 "to odt." org-pandoc-export-to-odt) (112 "to pptx and open." org-pandoc-export-to-pptx-and-open) (80 "to pptx." org-pandoc-export-to-pptx) (114 "to rtf and open." org-pandoc-export-to-rtf-and-open) (82 "as rtf." org-pandoc-export-as-rtf) (117 "to dokuwiki and open." org-pandoc-export-to-dokuwiki-and-open) (85 "as dokuwiki." org-pandoc-export-as-dokuwiki) (118 "to revealjs and open." org-pandoc-export-to-revealjs-and-open) (86 "as revealjs." org-pandoc-export-as-revealjs) (119 "to mediawiki and open." org-pandoc-export-to-mediawiki-and-open) (87 "as mediawiki." org-pandoc-export-as-mediawiki) (120 "to docx and open." org-pandoc-export-to-docx-and-open) (88 "to docx." org-pandoc-export-to-docx) (121 "to slidy and open." org-pandoc-export-to-slidy-and-open) (89 "as slidy." org-pandoc-export-as-slidy) (122 "to dzslides and open." org-pandoc-export-to-dzslides-and-open) (90 "as dzslides." org-pandoc-export-as-dzslides))) :options-alist ((:pandoc-options "PANDOC_OPTIONS" nil nil space) (:pandoc-extensions "PANDOC_EXTENSIONS" nil nil space) (:pandoc-metadata "PANDOC_METADATA" nil nil space) (:pandoc-variables "PANDOC_VARIABLES" nil nil space) (:epub-chapter-level "EPUB_CHAPTER_LEVEL" nil nil t) (:epub-cover-image "EPUB_COVER" nil nil t) (:epub-stylesheet "EPUB_STYLESHEET" nil nil t) (:epub-embed-font "EPUB_EMBED_FONT" nil nil newline) (:epub-meta "EPUB_META" nil nil newline) (:epub-css "EPUB_CSS" nil nil newline) (:epub-rights "EPUB_RIGHTS" nil nil newline) (:bibliography "BIBLIOGRAPHY")))
  byte-code("\302\303\304\305\306DD\307\310\311\312\10&\7\210\302\313\304\305\314DD\315\310\311\312\316&\7\210\302\317\304\305\320DD\321\310\311\312\322&\7\210\302\323\304\305\324..." [org-pandoc-option-type org-pandoc-menu-entry custom-declare-variable org-pandoc-options funcall function #f(compiled-function () #<bytecode 0x158bdfec6825>) "Pandoc options." :group org-pandoc :type org-pandoc-format-extensions #f(compiled-function () #<bytecode 0x158bdfec6831>) "List of Pandoc format extensions for specific outp..." (repeat symbol) org-pandoc-command #f(compiled-function () #<bytecode 0x158bdfec683d>) "Pandoc command." string org-pandoc-check-version #f(compiled-function () #<bytecode 0x158bdfec6849>) "Whether to check for a pandoc executable and its v..." boolean #f(compiled-function () #<bytecode 0x158bdf7df0a9>) "Pandoc menu-entry." list org-export-define-derived-backend pandoc org :translate-alist ((entity . org-pandoc-entity) (export-block . org-pandoc-export-block) (latex-environment . org-pandoc-latex-environ) (link . org-pandoc-link) (paragraph . org-pandoc-paragraph) (src-block . org-pandoc-src-block) (table . org-pandoc-table) (template . org-pandoc-template)) :menu-entry 112 "export via pandoc" :options-alist ((:pandoc-options "PANDOC_OPTIONS" nil nil space) (:pandoc-extensions "PANDOC_EXTENSIONS" nil nil space) (:pandoc-metadata "PANDOC_METADATA" nil nil space) (:pandoc-variables "PANDOC_VARIABLES" nil nil space) (:epub-chapter-level "EPUB_CHAPTER_LEVEL" nil nil t) (:epub-cover-image "EPUB_COVER" nil nil t) (:epub-stylesheet "EPUB_STYLESHEET" nil nil t) (:epub-embed-font "EPUB_EMBED_FONT" nil nil newline) (:epub-meta "EPUB_META" nil nil newline) (:epub-css "EPUB_CSS" nil nil newline) (:epub-rights "EPUB_RIGHTS" nil nil newline) (:bibliography "BIBLIOGRAPHY")) org-pandoc-epub-rights #f(compiled-function () #<bytecode 0x158bdf7df0c9>) "Pandoc option for EPUB copyrihgt statement." org-pandoc-options-for-asciidoc #f(compiled-function () #<bytecode 0x158bdf7df0d5>) "Pandoc options for asciidoc." org-pandoc-after-processing-asciidoc-hook #f(compiled-function () #<bytecode 0x158bdf7df0e1>) "Hook called after processing asciidoc." hook] 9)
  require(ox-pandoc)
  eval((require 'ox-pandoc) t)
  eval-expression((require 'ox-pandoc) nil nil 127)
  funcall-interactively(eval-expression (require 'ox-pandoc) nil nil 127)
  call-interactively(eval-expression nil nil)
  command-execute(eval-expression)

On GNU Emacs 27.2 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.25, cairo version 1.16.0) of 2021-08-25

Any idea?

Thanks!

[a-fent]

The active ox-pandoc repository from which MELPA packages are built is now https://github.com/emacsorphanage/ox-pandoc.

If the issue is unresolved, please do re-post it on the issue tracker there.