This is a forward of https://bugzilla.redhat.com/show_bug.cgi?id=1950158 Emacs 27.2 freezes when editing a file that ends with .mod (i.e. it opens the file in Modula 2 mode) after one enters a ':'. The UI simply hangs until one interrupts it with C-g. This happens with emacs -Q as well as with the Emacs flatpak (thus I assume that it is not Fedora specific). Cheers, Dan In GNU Emacs 27.2 (build 1, x86_64-redhat-linux-gnu, GTK+ Version 3.24.27, cairo version 1.16.0) of 2021-03-27 built on buildvm-x86-31.iad2.fedoraproject.org Windowing system distributor 'Fedora Project', version 11.0.12011000 System Description: Fedora 33 (Server Edition) Recent messages: Configured using: 'configure --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --program-prefix= --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-dbus --with-gif --with-jpeg --with-png --with-rsvg --with-tiff --with-xft --with-xpm --with-x-toolkit=gtk3 --with-gpm=no --with-xwidgets --with-modules --with-harfbuzz --with-cairo --with-json build_alias=x86_64-redhat-linux-gnu host_alias=x86_64-redhat-linux-gnu CC=gcc 'CFLAGS=-DMAIL_USE_LOCKF -O2 -flto=auto -ffat-lto-objects -fexceptions -g -grecord-gcc-switches -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection' LDFLAGS=-Wl,-z,relro PKG_CONFIG_PATH=:/usr/lib64/pkgconfig:/usr/share/pkgconfig' Configured features: XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS XWIDGETS LIBSYSTEMD JSON PDUMPER GMP Important settings: value of $LANG: en_US.utf8 locale-coding-system: utf-8-unix Major mode: notmuch-search Minor modes in effect: git-identity-magit-mode: t magit-todos-mode: t global-git-commit-mode: t magit-auto-revert-mode: t recentf-mode: t tracking-mode: t telega-patrons-mode: t hl-line-mode: t which-key-mode: t zoom-mode: t editorconfig-mode: t engine-mode: t modern-c++-font-lock-global-mode: t global-diff-hl-mode: t global-display-line-numbers-mode: t display-line-numbers-mode: t show-smartparens-global-mode: t show-smartparens-mode: t smartparens-global-mode: t smartparens-mode: t show-paren-mode: t projectile-mode: t flycheck-color-mode-line-mode: t global-flycheck-mode: t flycheck-mode: t company-statistics-mode: t helm-mode: t shell-dirtrack-mode: t helm--remap-mouse-mode: t async-bytecomp-package-mode: t override-global-mode: t tooltip-mode: t global-eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t buffer-read-only: t column-number-mode: 1 line-number-mode: t transient-mark-mode: t Load-path shadows: /home/dan/.emacs.d/elpa/cmake-mode-20210104.1831/cmake-mode hides /usr/share/emacs/site-lisp/cmake/cmake-mode /home/dan/.emacs.d/elpa/clang-format-20191106.950/clang-format hides /usr/share/emacs/site-lisp/site-start.d/clang-format Features: (shadow yaml-imenu ansible-doc company-ansible company-ansible-keywords yaml-mode tabify cal-move ledger-mode ledger-check ledger-texi ledger-test ledger-sort ledger-report ledger-reconcile ledger-occur ledger-fonts ledger-fontify ledger-state ledger-complete ledger-schedule ledger-init ledger-xact ledger-post ledger-exec ledger-navigate ledger-context ledger-commodities ledger-regex smartparens-c cc-mode cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs rpm-spec-mode pulse magit-extras forge-list forge-commands forge-semi forge-bitbucket buck forge-gogs gogs forge-gitea gtea forge-gitlab glab forge-github ghub-graphql treepy gsexp ghub forge-notify forge-revnote forge-pullreq forge-issue forge-topic bug-reference 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slack-message-share-buffer slack-message-edit-buffer slack-room-message-compose-buffer slack-message-compose-buffer slack-message-attachment-preview-buffer slack-action slack-star slack-reminder slack-search slack-message-reaction slack-message-editor slack-message-sender slack-message-notification alert log4e gntp slack-buffer slack-message-formatter slack-thread slack-im slack-channel slack-group slack-conversations slack-create-message slack-attachment slack-selectable slack-bot-message slack-user-message slack-file slack-message slack-message-faces slack-unescape slack-block slack-mrkdwn slack-usergroup slack-reaction slack-modeline slack-room slack-counts slack-user slack-bot slack-dnd-status slack-emoji slack-image slack-request slack-log request lui tracking shorten slack-team slack-team-ws slack-util websocket telega-obsolete telega telega-tdlib-events telega-webpage visual-fill-column telega-root telega-info telega-chat telega-modes image-mode exif telega-company telega-user telega-notifications notifications dbus telega-voip telega-msg telega-tme telega-sticker telega-i18n telega-vvnote bindat telega-ffplay telega-media telega-sort telega-filter telega-ins telega-folders telega-inline telega-tdlib telega-util rainbow-identifiers org-agenda org-refile smartparens-org org ob ob-tangle ob-ref ob-lob ob-table ob-exp org-macro org-footnote org-src ob-comint org-pcomplete org-list org-faces org-entities noutline outline org-version ob-emacs-lisp ob-core ob-eval org-table ol org-keys org-compat org-macs org-loaddefs svg dom telega-server telega-core cursor-sensor telega-customize emacsbug sendmail server notmuch hl-line notmuch-tree notmuch-jump notmuch-hello notmuch-show notmuch-print notmuch-crypto notmuch-mua notmuch-message notmuch-draft notmuch-maildir-fcc notmuch-address notmuch-company notmuch-parser notmuch-wash coolj notmuch-query goto-addr icalendar diary-lib diary-loaddefs cal-menu calendar cal-loaddefs notmuch-tag crm notmuch-lib notmuch-version notmuch-compat message rmc puny rfc822 mml mailabbrev gmm-utils mailheader mm-view mml-smime mml-sec epa derived epg epg-config gnus-util rmail rmail-loaddefs mail-utils text-property-search smime dig mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045 mm-util ietf-drums mail-prsvr company-oddmuse company-keywords company-etags company-gtags company-dabbrev-code company-dabbrev company-files company-clang company-capf company-cmake company-semantic company-template company-bbdb flyspell ispell highlight-indent-guides heaven-and-hell which-key init zoom shell-command+ eshell esh-cmd esh-ext esh-opt esh-proc esh-io esh-arg esh-module esh-groups esh-util wgrep flycheck-ledger editorconfig crux rfc-mode company-graphviz-dot graphviz-dot-mode avy company-web company-css web-completion-data powerline powerline-separators powerline-themes cap-words superword subword engine-mode go-projectile autorevert vc-git go-rename go-guru go-eldoc go-mode url url-proxy url-privacy url-expand 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