Support for (:underline (:style wave) when on terminal move is missing.
See src/xfaces.c, and the line:

    return false;               /* ttys can't use wave underlines */

Since ~3 years, support for curly underscores and colored underscores is
present in several terminal emulators. At least:
- Kitty: https://github.com/kovidgoyal/kitty/blob/master/protocol-extensions.asciidoc
- VTE
- iTerm2: https://gitlab.com/gnachman/iterm2/-/issues/6382

Example of implementations from other editors, such as Vim and Neovim
among others:
- https://github.com/vim/vim/issues/1306
- https://github.com/vim/vim/pull/2405
- https://github.com/neovim/neovim/issues/7479


In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.23, cairo version 1.16.0)
 of 2020-11-08, modified by Debian built on x86-ubc-01
System Description: Debian GNU/Linux bullseye/sid

Recent messages:
Loading /home/vic/.emacs.d/.local/cache/recentf...done
Starting new Ispell process aspell with english dictionary...done
Note: standard-indent, tab-width, evil-shift-width adjusted to 4
Session restored. Welcome back.
Wrote /home/vic/.doom.d/config.el
"config.el" 143L, 5373C written

Configured using:
 'configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --enable-libsystemd --with-pop=yes
 --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/27.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/27.1/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --with-mailutils --build
 x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
 --infodir=/usr/share/info --mandir=/usr/share/man --enable-libsystemd
 --with-pop=yes
 --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/27.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/27.1/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --with-mailutils --with-cairo
 --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars
 'CFLAGS=-g -O2 -fdebug-prefix-map=/build/emacs-6jKC2B/emacs-27.1+1=.
 -fstack-protector-strong -Wformat -Werror=format-security -Wall'
 'CPPFLAGS=-Wdate-time -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB NOTIFY
INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF
ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD
JSON PDUMPER LCMS2 GMP

Important settings:
  value of $LC_MONETARY: en_DK.UTF-8
  value of $LC_NUMERIC: en_DK.UTF-8
  value of $LC_TIME: en_DK.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8

Major mode: Elisp

Minor modes in effect:
  evil-traces-mode: t
  git-gutter-mode: t
  whitespace-mode: t
  global-evil-surround-mode: t
  evil-surround-mode: t
  eros-mode: t
  highlight-quoted-mode: t
  rainbow-delimiters-mode: t
  display-fill-column-indicator-mode: t
  vi-tilde-fringe-mode: t
  highlight-numbers-mode: t
  display-line-numbers-mode: t
  flyspell-lazy-mode: t
  flycheck-popup-tip-mode: t
  save-place-mode: t
  global-so-long-mode: t
  which-key-mode: t
  better-jumper-mode: t
  better-jumper-local-mode: t
  global-company-mode: t
  company-mode: t
  ivy-rich-mode: t
  ivy-mode: t
  evil-goggles-mode: t
  evil-escape-mode: t
  evil-snipe-override-mode: t
  evil-snipe-mode: t
  evil-snipe-override-local-mode: t
  evil-snipe-local-mode: t
  gcmh-mode: t
  global-hl-line-mode: t
  hl-line-mode: t
  winner-mode: t
  show-paren-mode: t
  smartparens-global-mode: t
  smartparens-mode: t
  ws-butler-global-mode: t
  ws-butler-mode: t
  global-undo-fu-session-mode: t
  undo-fu-session-mode: t
  undo-fu-mode: t
  global-flycheck-mode: t
  flycheck-mode: t
  solaire-global-mode: t
  solaire-mode: t
  projectile-mode: t
  xterm-mouse-mode: t
  xclip-mode: t
  hl-todo-mode: t
  outline-minor-mode: t
  yas-minor-mode: t
  savehist-mode: t
  recentf-mode: t
  doom-modeline-mode: t
  global-git-commit-mode: t
  async-bytecomp-package-mode: t
  persp-mode: t
  flyspell-mode: t
  shell-dirtrack-mode: t
  evil-mode: t
  evil-local-mode: t
  +popup-mode: t
  general-override-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  window-divider-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
/usr/share/emacs/site-lisp/llvm-11/llvm-mode hides /usr/share/emacs/site-lisp/llvm-6.0/llvm-mode
/usr/share/emacs/site-lisp/llvm-11/tablegen-mode hides /usr/share/emacs/site-lisp/llvm-6.0/tablegen-mode
/usr/share/emacs/site-lisp/llvm-11/emacs hides /usr/share/emacs/site-lisp/llvm-6.0/emacs
/usr/share/emacs/site-lisp/llvm-11/llvm-mode hides /usr/share/emacs/site-lisp/llvm-7/llvm-mode
/usr/share/emacs/site-lisp/llvm-11/tablegen-mode hides /usr/share/emacs/site-lisp/llvm-7/tablegen-mode
/usr/share/emacs/site-lisp/llvm-11/emacs hides /usr/share/emacs/site-lisp/llvm-7/emacs
/usr/share/emacs/site-lisp/llvm-11/llvm-mode hides /usr/share/emacs/site-lisp/llvm-8/llvm-mode
/usr/share/emacs/site-lisp/llvm-11/tablegen-mode hides /usr/share/emacs/site-lisp/llvm-8/tablegen-mode
/usr/share/emacs/site-lisp/llvm-11/emacs hides /usr/share/emacs/site-lisp/llvm-8/emacs
/usr/share/emacs/site-lisp/llvm-11/llvm-mode hides /usr/share/emacs/site-lisp/llvm-9/llvm-mode
/usr/share/emacs/site-lisp/llvm-11/tablegen-mode hides /usr/share/emacs/site-lisp/llvm-9/tablegen-mode
/usr/share/emacs/site-lisp/llvm-11/emacs hides /usr/share/emacs/site-lisp/llvm-9/emacs
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-autoloads hides /usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/debian-autoloads
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-el-autoloads hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-el-autoloads
/usr/share/emacs/site-lisp/elpa/debian-el-37/apt-sources hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/apt-sources
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-el hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-el
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-bug hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-bug
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-el-pkg hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-el-pkg
/usr/share/emacs/site-lisp/elpa/debian-el-37/deb-view hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/deb-view
/usr/share/emacs/site-lisp/elpa/debian-el-37/apt-utils hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/apt-utils
/usr/share/emacs/site-lisp/elpa/debian-el-37/gnus-BTS hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/gnus-BTS
/usr/share/emacs/site-lisp/elpa/debian-el-37/preseed hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/preseed
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-autoloads hides /usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-autoloads
/usr/share/emacs/site-lisp/elpa/devscripts-40/devscripts-pkg hides /usr/share/emacs/site-lisp/elpa-src/devscripts-40/devscripts-pkg
/usr/share/emacs/site-lisp/elpa/devscripts-40/devscripts-autoloads hides /usr/share/emacs/site-lisp/elpa-src/devscripts-40/devscripts-autoloads
/usr/share/emacs/site-lisp/elpa/devscripts-40/pbuilder-mode hides /usr/share/emacs/site-lisp/elpa-src/devscripts-40/pbuilder-mode
/usr/share/emacs/site-lisp/elpa/devscripts-40/devscripts hides /usr/share/emacs/site-lisp/elpa-src/devscripts-40/devscripts
/usr/share/emacs/site-lisp/elpa/devscripts-40/pbuilder-log-view-mode hides /usr/share/emacs/site-lisp/elpa-src/devscripts-40/pbuilder-log-view-mode
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/debian-copyright hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/debian-copyright
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/readme-debian hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/readme-debian
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/dpkg-dev-el hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/dpkg-dev-el
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/debian-control-mode hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/debian-control-mode
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-autoloads hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/debian-autoloads
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/dpkg-dev-el-autoloads hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/dpkg-dev-el-autoloads
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/debian-bts-control hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/debian-bts-control
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/dpkg-dev-el-pkg hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/dpkg-dev-el-pkg
/usr/share/emacs/site-lisp/elpa/dpkg-dev-el-37.0/debian-changelog-mode hides /usr/share/emacs/site-lisp/elpa-src/dpkg-dev-el-37.0/debian-changelog-mode
/usr/share/emacs/site-lisp/latex-cjk-thai/thai-word hides /usr/share/emacs/27.1/lisp/language/thai-word

Features:
(shadow sort mail-extr emacsbug sendmail amx cursor-sensor evil-traces
evil-ex lsp-mode lsp-protocol spinner network-stream
smartparens-markdown markdown-mode edit-indirect inline ht ewoc
dash-functional bindat flycheck-golangci-lint evil-collection-go-mode
go-mode find-file ffap etags fileloop flycheck-cask git-gutter
evil-collection-vc-git vc-git jka-compr auto-minor-mode disp-table
whitespace evil-embrace evil-surround embrace expand-region
text-mode-expansions the-org-mode-expansions er-basic-expansions
expand-region-core expand-region-custom eros highlight-quoted
rainbow-delimiters display-fill-column-indicator vi-tilde-fringe
highlight-numbers parent-mode display-line-numbers flyspell-lazy
flycheck-popup-tip evil-collection-popup popup ispell flyspell
face-remap saveplace so-long evil-collection-which-key which-key
better-jumper company-capf company evil-collection-ivy ivy-avy avy
ivy-rich counsel xdg ivy-xref evil-collection-xref xref project swiper
ivy delsel ivy-faces ivy-overlay colir evil-goggles pulse
evil-easymotion evil-escape evil-snipe gcmh hl-line winner paren
smartparens-config smartparens-text smartparens ws-butler
undo-fu-session undo-fu evil-collection-flycheck flycheck
doom-themes-ext-org doom-themes-ext-treemacs solaire-mode
doom-molokai-theme doom-themes doom-themes-base projectile ibuf-ext
evil-collection-ibuffer ibuffer ibuffer-loaddefs xt-mouse xclip
evil-terminal-cursor-changer color term/tmux term/xterm xterm
org-capture org-agenda org-refile evil-collection-magit-todos
magit-todos pcre2el rxt re-builder hl-todo evil-collection-grep grep
evil-collection-compile compile orgit smartparens-org org-yt org-element
avl-tree generator 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 evil-collection-outline noutline outline
org-version ob-emacs-lisp ob-core ob-eval org-table ol org-keys
org-compat org-macs org-loaddefs find-func evil-collection-calendar
cal-menu calendar cal-loaddefs github-review ghub-graphql treepy gsexp
ghub url-http url-gw nsm url-auth url url-proxy url-privacy url-expand
url-methods url-history url-cookie url-domsuf url-util mailcap let-alist
gnutls deferred a evil-collection-magit magit-autoloads magit-submodule
magit-obsolete magit-popup magit-blame magit-stash magit-reflog
magit-bisect magit-push magit-pull magit-fetch magit-clone magit-remote
magit-commit magit-sequence magit-notes magit-worktree magit-tag
magit-merge magit-branch magit-reset magit-files magit-refs magit-status
magit magit-repos magit-apply magit-wip magit-log which-func
evil-collection-imenu imenu magit-diff smerge-mode diff
evil-collection-diff-mode diff-mode magit-core magit-autorevert
autorevert filenotify magit-margin magit-transient magit-process
magit-mode lv core-packages package browse-url url-handlers url-parse
auth-source json map url-vars doom-snippets doom-snippets-lib yasnippet
evil-collection-elisp-mode elisp-mode help-mode savehist recentf
tree-widget dtrt-indent doom-modeline doom-modeline-segments
doom-modeline-env doom-modeline-core shrink-path f s all-the-icons
all-the-icons-faces data-material data-weathericons data-octicons
data-fileicons data-faicons data-alltheicons memoize git-commit
with-editor transient async-bytecomp async server magit-git
magit-section eieio eieio-core eieio-loaddefs magit-utils crm
evil-collection-log-edit log-edit message rmc puny evil-collection-dired
dired dired-loaddefs format-spec rfc822 mml mml-sec password-cache
evil-collection-epa evil-collection-custom cus-edit cus-start cus-load
wid-edit evil-collection-comint evil-collection annalist epa epg
epg-config gnus-util rmail rmail-loaddefs text-property-search time-date
mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045 mm-util
ietf-drums mail-prsvr mailabbrev mail-utils gmm-utils mailheader
pcvs-util add-log dash persp-mode evil evil-integration evil-maps
evil-commands reveal evil-jumps evil-command-window evil-types
evil-search shell pcomplete comint ansi-color evil-macros evil-repeat
evil-states evil-core advice evil-common windmove thingatpt rect
evil-digraphs evil-vars ring derived core-editor core-projects core-ui
edmacro kmacro easy-mmode core-keybinds pp general cl-extra easymenu seq
byte-opt cl-seq use-package-core bytecomp byte-compile cconv
core-modules rx cl core core-lib pcase cl-macs gv cl-loaddefs cl-lib
subr-x 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 lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow
isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu
font-core term/tty-colors frame minibuffer 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 simple abbrev obarray 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 cairo
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 635613 661479)
 (symbols 48 47597 48)
 (strings 32 155317 57250)
 (string-bytes 1 4780813)
 (vectors 16 78376)
 (vector-slots 8 1499396 183442)
 (floats 8 1014 2781)
 (intervals 56 1418 482)
 (buffers 1000 18))

-- 
Víctor Cuadrado Juan           me@viccuad.me

PGP key ID: 4096R: 0xA2591E231E251F36
Key fingerprint: E3C5 114C 0C5B 4C49 BA03  0991 A259 1E23 1E25 1F36
My signed E-Mails are trustworthy.