bug#33728: 27.0.50; [HarfBuzz] cursor flickering or blinking very fast

[jvshahid]

When I compile Emacs using the harfbuzz branch, my cursor (which is a
filled box) seems to be flickering or blinking very fast.


In GNU Emacs 27.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.1)
 of 2018-12-13 built on amun
Repository revision: 981b3d292aff49452c2b5f0217b57ec1a2829a8b
Repository branch: harfbuzz
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description: Arch Linux

Recent messages:
Omitting...
(Nothing to omit)
Omitting...
Omitted 2 lines.
Parinfer: Paren Mode, use C-x p to switch to Indent Mode.
scroll-up-command: End of buffer [13 times]
scroll-down-command: Beginning of buffer
Mark set
Mark saved where search started
Making completion list... [2 times]

Configured using:
 'configure --prefix=/home/jvshahid/bin/emacs-harbuzz --with-xpm=no
 --with-jpeg=no --with-gif=no --with-tiff=no'

Configured features:
PNG RSVG SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL GNUTLS LIBXML2
FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS
LIBSYSTEMD JSON LCMS2 GMP

Important settings:
  value of $LC_COLLATE: en_US.UTF-8
  value of $LC_CTYPE: en_US.UTF-8
  value of $LC_MESSAGES: en_US.UTF-8
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Emacs-Lisp

Minor modes in effect:
  diff-auto-refine-mode: t
  parinfer-mode: t
  global-auto-complete-mode: t
  auto-complete-mode: t
  show-paren-mode: t
  display-time-mode: t
  display-battery-mode: t
  global-auto-revert-mode: t
  winner-mode: t
  flx-ido-mode: t
  straight-use-package-mode: t
  straight-package-neutering-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
/home/jvshahid/.emacs.d/straight/build/cl-lib/cl-lib hides 
/home/jvshahid/bin/emacs-harbuzz/share/emacs/27.0.50/lisp/emacs-lisp/cl-lib
/home/jvshahid/.emacs.d/straight/build/seq/seq hides 
/home/jvshahid/bin/emacs-harbuzz/share/emacs/27.0.50/lisp/emacs-lisp/seq
/home/jvshahid/.emacs.d/straight/build/cl-generic/cl-generic hides 
/home/jvshahid/bin/emacs-harbuzz/share/emacs/27.0.50/lisp/emacs-lisp/cl-generic

Features:
(shadow sort mail-extr emacsbug message rmc puny format-spec rfc822 mml
mml-sec password-cache epa derived epg epg-config gnus-util rmail
rmail-loaddefs time-date mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils misearch multi-isearch vc-git
diff-mode dired-aux parinfer-ext paredit parinfer ediff-merg ediff-wind
ediff-diff ediff-mult ediff-help ediff-init ediff-util ediff mode-local
parinferlib flycheck json map find-func dash flymake-proc flymake
auto-complete-config auto-complete popup lsp-rust-autoloads
rust-mode-autoloads exwm-randr xcb-randr exwm-config exwm exwm-input
xcb-keysyms xcb-xkb exwm-manage exwm-floating xcb-cursor xcb-render
exwm-layout exwm-workspace exwm-core xcb-ewmh xcb-icccm xcb xcb-xproto
xcb-types xcb-debug exwm-autoloads xelb-autoloads cl-generic-autoloads
rect dired-x dired dired-loaddefs tango-dark-theme warnings server paren
time battery cus-start cus-load autorevert filenotify winner flx-ido
advice flx ido seq seq-25 edmacro kmacro edit-indirect-autoloads
parinfer-autoloads ginkgo-mode-autoloads pianobar-autoloads
concourse-mode-autoloads hierarchy-autoloads robe-autoloads
inf-ruby-autoloads rvm-autoloads git-link-autoloads
company-lsp-autoloads company-autoloads lsp-java-autoloads ht-autoloads
f-autoloads lsp-ui-autoloads dash-functional-autoloads
lsp-mode-autoloads flx-ido-autoloads flx-autoloads wgrep-autoloads
ac-cider-autoloads request-autoloads helm-autoloads helm-core-autoloads
paredit-autoloads flycheck-clojure-autoloads flycheck-autoloads
cider-autoloads sesman-autoloads seq-autoloads queue-autoloads
clojure-mode-autoloads go-rename-autoloads ace-window-autoloads
avy-autoloads dockerfile-mode-autoloads s-autoloads
yasnippet-snippets-autoloads yasnippet-autoloads
go-autocomplete-autoloads auto-complete-autoloads go-eldoc-autoloads
protobuf-mode-autoloads markdown-mode-autoloads go-guru-autoloads
arduino-mode-autoloads ede/auto cl-seq eieio eieio-core eieio-loaddefs
spinner-autoloads yaml-mode-autoloads etags-select-autoloads
magit-autoloads magit-popup-autoloads git-commit-autoloads
with-editor-autoloads ghub-autoloads treepy-autoloads graphql-autoloads
dash-autoloads async-autoloads projectile-autoloads pkg-info-autoloads
epl-autoloads eshell-z-autoloads go-mode-autoloads debbugs-autoloads
finder-inf popup-autoloads cl-lib-autoloads straight-autoloads rx
compile comint ansi-color ring cl-extra straight info autoload
radix-tree lisp-mnt easy-mmode pcase subr-x byte-opt checkdoc thingatpt
help-mode easymenu elec-pair cl-macs gv cl-loaddefs cl-lib bytecomp
byte-compile cconv mule-util tooltip eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list replace
newcomment text-mode elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock
font-lock syntax facemenu font-core term/tty-colors frame cl-generic
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 charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray minibuffer
cl-preloaded nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote threads dbusbind
inotify lcms2 dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 291123 290885)
 (symbols 48 39754 10)
 (strings 32 88162 46905)
 (string-bytes 1 3041891)
 (vectors 16 50442)
 (vector-slots 8 1151097 225990)
 (floats 8 130 790)
 (intervals 56 707 247)
 (buffers 992 21))