There has been no response to the bug bug#70387 or the issue reported on the yasnippet github page on April 12, 2024. I have created an Ert test for it. yas-expand in yasnippet-0.14.1.0.20250112.175154 throws warning p.s. is there a more idiomatic way of checking for warnings in Ert "⛔ Warning (yasnippet): Couldn’t find: \"[[:space:]\n]*\\\"[[:space:]\n]*\\\\(\\\\)[[:space:]\n]*\\\"\"\n" ;; rm -rf ~/tmp/yas-test ;; mkdir !$ ;; emacs --quick --init-directory=!$ this-file (require 'package) (add-to-list 'package-archives '("gnu-devel" . "https://elpa.gnu.org/devel/") t) (package-initialize) (package-refresh-contents) (package-install 'yasnippet) (use-package yasnippet) (defun warning-buffer-contents-no-properties () "Return contents of *Warnings* buffer, without properties" (when-let* ((buf (get-buffer "*Warnings*"))) (with-current-buffer buf (buffer-substring-no-properties (point-min) (point-max))))) (defun my-create-yasnippet-snippets () "Create a snippet called `could-not-find-space'. Add it to the group `emacs-lisp-mode' Allow `org-mode' to inherit `emacs-lisp-mode' snippets" (let* ((snippet-key "could-not-find-space") (snippet-content (concat " ($1)\n" " \"$0\"")) (snippet-def (list snippet-key snippet-content nil nil nil nil nil)) (snippet-defs (list snippet-def)) (mode 'emacs-lisp-mode)) (yas-define-snippets mode snippet-defs) (yas--define-parents 'org-mode '(emacs-lisp-mode)))) (ert-deftest could-not-find-space () "yas-expand should not throw the warning - Couldn't find [[:space:]]" (my-create-yasnippet-snippets) (ignore-error (kill-buffer "*Warnings")) (let ((org-mode-buffer-contents (concat "#+name: test \n" "#+begin_src emacs-lisp\n" " 2\n" " could-not-find-space| \n" "#+end_src"))) (with-temp-buffer (org-mode) (setq org-edit-src-content-indentation 1) (yas-minor-mode 1) (insert org-mode-buffer-contents) (goto-char (point-min)) (search-forward "|") (delete-char -1) (call-interactively 'yas-expand) (buffer-substring-no-properties (point-min) (point-max)))) (should (equal (warning-buffer-contents-no-properties) nil))) (ert t) In GNU Emacs 31.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.38, cairo version 1.16.0) of 2025-02-21 built on slug Repository revision: 4411d0de1d5cbf308440982084ad7e15a18efaf2 Repository branch: master Windowing system distributor 'The X.Org Foundation', version 11.0.12101007 System Description: LMDE 6 (faye) Configured using: 'configure --with-mailutils --with-modules --with-imagemagick --prefix=/home/no-control/local/installs --bindir=/home/no-control/local/bin --with-native-compilation --with-tree-sitter' Configured features: CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GSETTINGS HARFBUZZ IMAGEMAGICK JPEG LCMS2 LIBSELINUX LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11 XDBE XIM XINERAMA XINPUT2 XPM XRANDR GTK3 ZLIB Important settings: value of $LANG: en_GB.UTF-8 value of $XMODIFIERS: @im=ibus locale-coding-system: utf-8-unix Major mode: ERT-Results Minor modes in effect: tooltip-mode: t global-eldoc-mode: t show-paren-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t minibuffer-regexp-mode: t buffer-read-only: t line-number-mode: t indent-tabs-mode: t transient-mark-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug oc-basic ol-eww eww vtable mule-util url-queue mm-url ol-rmail ol-mhe ol-irc ol-info ol-gnus nnselect gnus-art mm-uu mml2015 mm-view mml-smime smime dig gnus-sum shr pixel-fill kinsoku url-file svg dom gnus-group gnus-undo gnus-start gnus-dbus dbus xml gnus-cloud nnimap nnmail mail-source utf7 nnoo parse-time gnus-spec gnus-int gnus-range gnus-win gnus nnheader range ol-docview doc-view filenotify jka-compr image-mode exif ol-bibtex bibtex iso8601 ol-bbdb ol-w3m ol-doi org-link-doi use-package-core ox-odt rng-loc rng-uri rng-parse rng-match rng-dt rng-util rng-pttrn nxml-parse nxml-ns nxml-enc xmltok nxml-util ox-latex ox-icalendar org-agenda ox-html table ox-ascii ox-publish ox org-attach org-element org-persist org-id org-refile org-element-ast inline avl-tree generator org ob ob-tangle ob-ref ob-lob ob-table ob-exp org-macro org-src sh-script smie treesit executable ob-comint org-pcomplete pcomplete org-list org-footnote org-faces org-entities noutline outline org-version ob-emacs-lisp ob-core ob-eval org-cycle org-table ol org-fold org-fold-core org-keys oc org-loaddefs thingatpt cal-menu calendar cal-loaddefs org-compat org-macs format-spec ert-x ert ewoc warnings edebug debug backtrace find-func color yasnippet pcase cl-extra help-mode yasnippet-autoloads easy-mmode loaddefs-gen lisp-mnt radix-tree tar-mode arc-mode archive-mode cus-edit pp cus-start cus-load wid-edit mm-archive message sendmail yank-media dired dired-loaddefs rfc822 mml mml-sec epa derived gnus-util time-date mailabbrev gmm-utils mailheader mm-decode mm-bodies mm-encode mail-utils gnutls network-stream url-cache url-http url-auth mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr url-gw nsm puny compile text-property-search comint ansi-osc ansi-color ring comp-run comp-common rx epg rfc6068 epg-config finder-inf package browse-url xdg url url-proxy url-privacy url-expand url-methods url-history url-cookie generate-lisp-file url-domsuf url-util mailcap url-handlers url-parse auth-source cl-seq eieio eieio-core cl-macs icons password-cache json subr-x map byte-opt gv bytecomp byte-compile url-vars cl-loaddefs cl-lib rmc iso-transl tooltip cconv eldoc paren electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel term/x-win x-win term/common-win x-dnd touch-screen tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch easymenu timer select scroll-bar mouse jit-lock font-lock syntax font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic indonesian philippine cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite emoji-zwj charscript charprop case-table epa-hook jka-cmpr-hook help abbrev obarray oclodb files window text-properties overlay sha1 md5 base64 format env code-pages mule custom widget keymap hashtable-print-readable backquote threads dbusbind inotify lcms2 dynamic-setting system-font-setting font-render-setting cairo gtk x-toolkit xinput2 x multi-tty move-toolbar make-network-process tty-child-frames native-compile emacs) Memory information: ((conses 16 411783 32541) (symbols 48 30614 0) (strings 32 124515 6677) (string-bytes 1 3456886) (vectors 16 61641) (vector-slots 8 591036 21567) (floats 8 455 85) (intervals 56 787 0) (buffers 992 15))