Bug#1108535: systemd: Background tint and emojis are often not supported and don't fail gracefully

[urosm]

Package: systemd
Version: 257.7-1
Severity: normal

Dear Maintainer,

Systemd's tools keep insisting on using emojis and modifying the
terminal colors.  These are arguably misfeatures as they assume a lot
about the user's environment, and don't fail gracefully when those
assumptions are often not met.

`run0` and `systemd-analyze security`, for example, try to print emojis.
Not sure what my setup should be, but I'm using a terminal and a font
both readily available in the main debian repositories.

When running `systemd-analyze security` my terminal prints the square
glyph instead of the, I assume, happy or frowny faces.  The neutral and
horrified faces are printed, but are not really readable, and I don't
understand their function as they're printed next to the literal word
the emojis are supposedly reacting to.

Running `run0` hijacks the prompt with a square glyph again.  Supposedly
it should be the idcard emoji.  It also tries to print the emoji in the
window title.  Even if the font supported these emojis, their meaning is
confusing.  Arguably it amounts to introducing another unexpected
language to the users shell.

`run0` also tints the terminal background slightly red.  The yellow
formatted text that `journalctl` prints is not readable.  `dmesg` output
is a bit better as dmesg respects the 8 colors set in the terminal and I
took care in setting them so that they meet WCAG AAA contrast ratios.
The red tint of systemd-run degrades the contrast ratio a bit.

I can see some of these issues have been brought up in the github issue
tracker upstream, but have not been acted upon.  The features can be
disabled with environment variables:

```
export SYSTEMD_EMOJI=0 # or SYSTEMD_UTF8=0
export SYSTEMD_TINT_BACKGROUND=0
export SYSTEMD_ADJUST_TERMINAL_TITLE=0
```

I would expect these features to be disabled without the user's explicit
action as they degrade clarity and readability, but don't add any
functionality.

-- Package-specific info:

-- System Information:
Debian Release: 13.0
   APT prefers unstable
   APT policy: (500, 'unstable'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 6.12.32-amd64 (SMP w/8 CPU threads; PREEMPT)
Locale: LANG=sl_SI.UTF-8, LC_CTYPE=sl_SI.UTF-8 (charmap=UTF-8), 
LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages systemd depends on:
ii  libacl1            2.3.2-2+b1
ii  libapparmor1       4.1.0-1
ii  libc6              2.41-9
ii  libmount1          2.41-5
ii  libpam0g           1.7.0-5
ii  libseccomp2        2.6.0-2
ii  libselinux1        3.8.1-1
ii  libssl3t64         3.5.0-2
ii  libsystemd-shared  257.7-1
ii  libsystemd0        257.7-1
ii  mount              2.41-5

Versions of packages systemd recommends:
ii  dbus [default-dbus-system-bus]   1.16.2-2
ii  linux-sysctl-defaults            4.12
pn  systemd-cryptsetup               <none>
ii  systemd-timesyncd [time-daemon]  257.7-1

Versions of packages systemd suggests:
pn  libtss2-tcti-device0  <none>
ii  polkitd               126-2
pn  systemd-boot          <none>
pn  systemd-container     <none>
pn  systemd-homed         <none>
pn  systemd-repart        <none>
pn  systemd-resolved      <none>
pn  systemd-userdbd       <none>

Versions of packages systemd is related to:
ii  dbus-user-session  1.16.2-2
pn  dracut             <none>
ii  initramfs-tools    0.148.3
ii  libnss-systemd     257.7-1
ii  libpam-systemd     257.7-1
ii  udev               257.7-1

-- no debconf information

-- 
urosm