I am trying out project based search via project-find-regexp, but I get the error:

vc-call-backend: VC method not implemented for backend: find-ignore-file, CVS

How can I fix this? I assume this is a CVS specific problem. Is there way to make CVS working with the project system? (Or just ignoring the CVS aspect when doing the project search?)

  • Apparently project (and thus vc) think your project is using CVS as its version control. Check the docs for each to see how to explicitly set the version control system for your project. Or you can customize vc-enabled-backends, to set which backends vc will use. If you're just interested in searching, maybe Emacs integration for one of the "fast search tools" (ack, ag, ripgrep, etc.) would be more suited to your needs.
    – nega
    May 26, 2021 at 21:57
  • @nega Thx for chiming in. The project is using CVS! I thought Emacs supports CVS.
    – halloleo
    May 26, 2021 at 23:46
  • oh my! ;) Emacs does support CVS with vc, but not for ignoring files apparently. In my copy of vc the backend specific functions are only implemented for git, bzr, hg, and mtn. This might be helpful though github.com/wolfmanx/vc-ign
    – nega
    May 27, 2021 at 1:53
  • Does CVS have anything similar to svn propget svn:ignore?
    – Dmitry
    May 27, 2021 at 16:28
  • Yes, it does. You can create a file called cvsignore where you list the file patterns that you want CVS to ignore. See the documentation online (gnu.org/software/trans-coord/manual/cvs/html_node/…).
    – db48x
    May 29, 2021 at 11:28

1 Answer 1


For a quick workaround, you can try adding this definition to your init script:

(defun vc-cvs-find-ignore-file (file)
  (expand-file-name ".cvsignore" (file-name-directory file)))
  • Thx. Looks promising. Will try it out next week.
    – halloleo
    May 29, 2021 at 0:04
  • 2
    It’s an odd oversight for the vc package to be missing this function; someone should file a bug.
    – db48x
    May 29, 2021 at 11:29
  • Seems like not too many people care about CVS these days. But a report will be good to have indeed.
    – Dmitry
    May 29, 2021 at 17:32
  • 1
    The function works like a charm. Will file a bug report to the bug-gnu-emacs list.
    – halloleo
    Jun 1, 2021 at 6:41

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