bug#70517: 29.3; suspicious error message from compile command in Emacs 29.3

[Thomas Düssel]

The following error message appears in the terminal from which emacs was
started every time I use the 'compile' command:

> emacs: writing to child signal FD: Invalid argument

The compilation itself (via make) works perfectly fine. Only this new
message is a bit annoying. And so cryptic, isn't it? It did not appear
up until the latest update.

This error message (or whatever it is) appears also, when I start emacs
from a non-X tty (Ctrl + Alt + F2) and with '-Q' option. To be precise,
it appears when I use 'M-x compile' and for longer compilation processes
it appears at the end of the compilation, not at the beginning.

Best Regards,

Tom

In GNU Emacs 29.3 (build 1, x86_64-slackware-linux-gnu, GTK+ Version
 3.24.31, cairo version 1.16.0) of 2024-03-24 built on
 z-mp.slackware.lan
Windowing system distributor 'The X.Org Foundation', version 11.0.12014000
System Description: Slackware 15.0 x86_64

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
 --program-prefix= --program-suffix= --mandir=/usr/man
 --infodir=/usr/info --without-gconf --without-gsettings --with-modules
 --with-x --with-x-toolkit=gtk3 --with-pdumper=no --with-dumping=unexec
 --build=x86_64-slackware-linux 'CFLAGS=-O2 -fPIC''

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM HARFBUZZ JPEG JSON LCMS2
LIBXML2 MODULES NOTIFY INOTIFY PNG RSVG SECCOMP SOUND SQLITE3 THREADS
TIFF TOOLKIT_SCROLL_BARS UNEXEC WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

Important settings:
  value of $LC_COLLATE: C
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: GNUmakefile

Minor modes in effect:
  display-line-numbers-mode: t
  windmove-mode: t
  winner-mode: t
  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
  column-number-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:
/usr/share/emacs/29.3/lisp/textmodes/css-mode hides
~/.emacs.d/user-lisp/css-mode

Features:
(shadow sort mail-extr emacsbug message yank-media puny dired
dired-loaddefs rfc822 mml mml-sec epa derived epg rfc6068 epg-config
gnus-util text-property-search 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 vc-git diff-mode
easy-mmode vc-dispatcher make-mode display-line-numbers buffer-move
windmove winner ring finder-inf package browse-url 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 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 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 dbusbind inotify lcms2 dynamic-setting font-render-setting cairo
move-toolbar gtk x-toolkit xinput2 x multi-tty make-network-process
emacs)

Memory information:
((conses 16 243254 13743)
 (symbols 48 27947 2)
 (strings 32 78044 1812)
 (string-bytes 1 1836829)
 (vectors 16 26114)
 (vector-slots 8 687379 23398)
 (floats 8 62 78)
 (intervals 56 336 0)
 (buffers 976 11))