1. Visit remote file on an OSX system using /scp:hostname:/path/to/file
2. Modify buffer
3. Save
4. Note buffer-file-coding-system has updated to utf-8-mac (and (Mac) now
listed
in modeline).
5. Modify and Save again and the file line endings will be converted to
carriage returns.

I used git bisect to find commit
47fe7a5983a97c3e806e90340f3cd6ab3f0c49b2 introduced this behavior. Prior
to 47fe7a59 emacs would not modify the line endings of the file.   I
believe utf-8-mac is only for Mac Classic files.

In GNU Emacs 29.0.50 (build 12, x86_64-pc-linux-gnu, X toolkit, cairo
version 1.16.0, Xaw3d scroll bars)
of 2022-06-02 built on hostname
Repository revision: 47fe7a5983a97c3e806e90340f3cd6ab3f0c49b2
Repository branch: HEAD
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Ubuntu 22.04 LTS

Configured using:
'configure --with-x-toolkit=lucid --without-native-compilation'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY
INOTIFY PDUMPER PNG RSVG SECCOMP SOUND THREADS TIFF TOOLKIT_SCROLL_BARS
X11 XAW3D XDBE XIM XPM LUCID ZLIB

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

Major mode: ELisp/d

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 rmc 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 smtpmail
auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache json map sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils misearch multi-isearch vc-git diff-mode easy-mmode
vc-dispatcher cl-loaddefs cl-lib seq gv subr-x byte-opt bytecomp
byte-compile cconv 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 nadvice simple 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 abbrev obarray oclosure cl-preloaded button
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 system-font-setting font-render-setting cairo x-toolkit
x multi-tty make-network-process emacs)

Memory information:
((conses 16 55245 10587)
(symbols 48 7079 1)
(strings 32 21097 1688)
(string-bytes 1 665408)
(vectors 16 14212)
(vector-slots 8 196342 11371)
(floats 8 25 55)
(intervals 56 250 9)
(buffers 992 12))