Subject: 29.1; Emacs client on Windows can't connect to the daemon on WSL over TCP

From: user@pontos
Date: Thu, 7 Sep 2023 15:10:59 -0400

Hello,

I'm trying to connect Emacs client running on Windows over TCP to the Emacs
server running inside WSL.

# Inside WSL shell:
(cat <<EOF
(setq server-host "WSL_IP_ADDRESS_HERE")
(setq server-port 12345)
(setq server-use-tcp t)
(server-start)
EOF
) > server-config.el
emacs -Q -l server-config.el --daemon

# On Windows
# Map network drive \\wsl.localhost\Ubuntu as, e.g. W:
# Then in PowerShell:
$env:EMACS_SERVER_FILE=W:\home\user\.emacs.d\server\server
& 'C:\Program Files\Emacs\emacs-29.1\bin\emacsclientw.exe' -c -n

Client will first display message window saying that it connected to the
remote socket, and after clicking [OK] button, error message appears
saying "*ERROR*: Could not open file: CONOUT$".

In GNU Emacs 29.1 (build 2, x86_64-w64-mingw32) of 2023-08-02 built on
 AVALON
Windowing system distributor 'Microsoft Corp.', version 10.0.22621
System Description: Microsoft Windows 10 Pro for Workstations (v10.0.2009.22621.2215)

Configured using:
 'configure --with-modules --without-dbus --with-native-compilation=aot
 --without-compress-install --with-tree-sitter CFLAGS=-O2'

Configured features:
ACL GIF GMP GNUTLS HARFBUZZ JPEG JSON LCMS2 LIBXML2 MODULES NATIVE_COMP
NOTIFY W32NOTIFY PDUMPER PNG RSVG SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP XPM ZLIB

(NATIVE_COMP present but libgccjit not available)

Important settings:
  value of $LANG: ENU
  locale-coding-system: cp65001

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  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
  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 message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date subr-x mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils rmc iso-transl tooltip cconv eldoc paren electric
uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel dos-w32
ls-lisp disp-table term/w32-win w32-win w32-vars term/common-win
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 oclosure cl-preloaded button
loaddefs theme-loaddefs faces cus-face macroexp files window
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget keymap hashtable-print-readable backquote threads
w32notify w32 lcms2 multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 49664 11502)
 (symbols 48 5188 0)
 (strings 32 15157 1304)
 (string-bytes 1 415581)
 (vectors 16 10077)
 (vector-slots 8 254971 15480)
 (floats 8 25 37)
 (intervals 56 302 0)
 (buffers 984 11))