now works, with bibtex-completion PR

bibtex-actions.el

@@ -83,7 +83,9 @@ may be indicated with the same icon but a different face."
 
 (when bibtex-actions-rich-ui
   (setq bibtex-completion-display-formats
-        '((t . "${author:20}   ${title:48}   ${year:4}"))))
+        '((t . "${author:20}   ${title:48}   ${year:4}")))
+  (setq bibtex-completion-display-formats-suffix
+        '((t . "${=type=}"))))
 
 ;;; Keymap
 
@@ -138,7 +140,9 @@ key associated with each one."
                     (bibtex-completion-get-value "keywords" candidate) ""))
           (reftype (bibtex-completion-get-value "=type=" candidate))
           (citekey (bibtex-completion-get-value "=key=" candidate))
-          (suffix (s-lex-format "		(${citekey}, ${reftype}) ${tags}")))
+          ; TODO: add separation between target and suffix
+          (suffix  (bibtex-completion-format-entry candidate (1- (frame-width))
+                        bibtex-completion-display-formats-suffix-internal)))
    (cons
     ;; Here use one string for display, and the other for search.
     ;; The candidate string we use is very long, which is a bit awkward