title: Citeproc error after updating to debian buster - void variable bibtex completion display formats
body: <p>I am able to insert article citations in org mode using org-cite-insert but when i try to export it to html i get the following error. It worked beautifully a day ago but is acting up after i basically powerwashed my chromebook to install debian buster. Would really appreciate any advice.
  Thanks.</p>
  <pre><code>Debugger entered--Lisp error: (void-variable bibtex-completion-display-formats)
    byte-code(&quot;\306 \210\307\10\310\11!\n#\210\311\303\312\313\314DD\315\316\317\320\321&amp;\7\210\322\13G\13\323\3\3X\203G\0\1:\203G\0\1@\262\1\324\1@\f...&quot; [org-mode-map org-ref-insert-cite-key org-ref-insert-link-function org-ref-bibtex-completion-actions helm-source-bibtex bibtex-completion-format-citation-functions org-ref-bibtex-completion-completion define-key kbd custom-declare-variable funcall function #f(compiled-function () #&lt;bytecode 0x1f400016fe914&gt;) &quot;Cons cells of string and function to set the actio...&quot; :type (alist :key-type (string) :value-type (function)) :group org-ref 0 nil helm-delete-action-from-source helm-add-action-to-source org-ref-bibtex-completion-format-org #f(compiled-function () #&lt;bytecode 0x1f4010b9da114&gt;) &quot;Function for how `helm-bibtex' inserts citations.&quot; org-mode org-ref-helm-insert-cite-link org-ref-cite-click-helm org-ref-bibtex-completion-add-keywords-field #f(compiled-function () #&lt;bytecode 0x1f400016fe5d4&gt;) &quot;Whether to add the `keywords' field to bibtex-comp...&quot; boolean keywords &quot;keywords&quot; alist-get t &quot;{keywords:&quot; string-match &quot; ${keywords:31}&quot; org-ref-insert-cite-function org-ref-cite-onclick-function bibtex-completion-additional-search-fields bibtex-completion-display-formats inhibit-changing-match-data] 8)
    require(org-ref-helm-bibtex)
    eval-buffer(#&lt;buffer  *load*-422164&gt; nil &quot;/home/pixel/.emacs.d/elpa/org-ref-2.0.0/org-r...&quot; nil t)  ; Reading at buffer position 1644
    load-with-code-conversion(&quot;/home/pixel/.emacs.d/elpa/org-ref-2.0.0/org-r...&quot; &quot;/home/pixel/.emacs.d/elpa/org-ref-2.0.0/org-r...&quot; nil t)
    require(org-ref)
    eval-buffer(#&lt;buffer  *load*&gt; nil &quot;/home/pixel/.emacs.d/elpa/citeproc-org-0.2.4/...&quot; nil t)  ; Reading at buffer position 1539
    load-with-code-conversion(&quot;/home/pixel/.emacs.d/elpa/citeproc-org-0.2.4/...&quot; &quot;/home/arcotpixel/.emacs.d/elpa/citeproc-org-0.2.4/...&quot; nil t)
    citeproc-org-render-references(html)
    run-hook-with-args(citeproc-org-render-references html)
    org-export-as(html nil nil nil (:output-file &quot;article.html&quot;))
    org-export-to-file(html &quot;article.html&quot; nil nil nil nil nil)
    org-html-export-to-html(nil nil nil nil)
    org-export-dispatch(nil)
    funcall-interactively(org-export-dispatch nil)
    call-interactively(org-export-dispatch nil nil)
    command-execute(org-export-dispatch)
  </code></pre>