Steps to reproduce:

1. emacs -q

2. M-x shell

3. echo start

sudo pacman -S nyancat

echo end

4. See, that "end" doesn't get printed.

~ > echo start

sudo pacman -S nyancat

echo end

echo start

start

~ > sudo pacman -S nyancat

warning: nyancat-1.5.2-2 is up to date -- reinstalling

resolving dependencies...

looking for conflicting packages...

Package (1)        Old Version  New Version  Net Change

community/nyancat  1.5.2-2      1.5.2-2        0.00 MiB

Total Installed Size:  0.06 MiB

Net Upgrade Size:      0.00 MiB

:: Proceed with installation? [Y/n] y

y

(1/1) checking keys in keyring                                                                                   [####################################################################] 100%

(1/1) checking package integrity                                                                                 [####################################################################] 100%

(1/1) loading package files                                                                                      [####################################################################] 100%

(1/1) checking for file conflicts                                                                                [####################################################################] 100%

(1/1) checking available disk space                                                                              [####################################################################] 100%

:: Processing package changes...

(1/1) reinstalling nyancat                                                                                       [####################################################################] 100%

:: Running post-transaction hooks...

(1/2) Reloading system manager configuration...

(2/2) Arming ConditionNeedsUpdate...

~ >

In GNU Emacs 28.2 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.36, cairo version 1.17.6)

 of 2023-01-03 built on 2

Windowing system distributor 'The X.Org Foundation', version 11.0.12101008

System Description: Arch Linux

Configured using:

 'configure --sysconfdir=/etc --prefix=/usr --libexecdir=/usr/lib

 --localstatedir=/var --with-cairo --with-harfbuzz --with-libsystemd

 --with-modules --with-x-toolkit=gtk3 'CFLAGS=-march=x86-64

 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2

 -Wformat -Werror=format-security -fstack-clash-protection

 -fcf-protection -g

 -ffile-prefix-map=/build/emacs/src=/usr/src/debug/emacs -flto=auto'

 'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now -flto=auto''

Configured features:

ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG

JSON LCMS2 LIBOTF LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY INOTIFY

PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS X11 XDBE

XIM XPM GTK3 ZLIB

Important settings:

  value of $LANG: en_US.UTF-8

  locale-coding-system: utf-8-unix

Major mode: Shell

Minor modes in effect:

  shell-dirtrack-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

  auto-composition-mode: t

  auto-encryption-mode: t

  auto-compression-mode: t

  line-number-mode: t

  indent-tabs-mode: t

  transient-mark-mode: t

Load-path shadows:

None found.

Features:

(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs

rfc822 mml mml-sec epa derived epg rfc6068 epg-config gnus-util rmail

rmail-loaddefs auth-source cl-seq eieio eieio-core cl-macs

eieio-loaddefs password-cache json map text-property-search seq byte-opt

gv bytecomp byte-compile cconv mm-decode mm-bodies mm-encode mail-parse

rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045

ietf-drums mm-util mail-prsvr mail-utils shell pcomplete comint

ansi-color ring time-date subr-x cl-loaddefs cl-lib iso-transl tooltip

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 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 emoji-zwj charscript charprop

case-table epa-hook jka-cmpr-hook help simple abbrev obarray

cl-preloaded nadvice button loaddefs faces cus-face macroexp files

window 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 64126 11476)

 (symbols 48 7189 1)

 (strings 32 20848 1844)

 (string-bytes 1 694151)

 (vectors 16 14694)

 (vector-slots 8 196111 12327)

 (floats 8 24 36)

 (intervals 56 801 1)

 (buffers 992 12))