'lxsu exo-open test.txt' does not open text editor while 'sudo --set-home exo-open test.txt' does

[adrelanos]

Expected Behavior

• Same behavior as with sudo --set-home.
• Editor opening.

Current Behavior

lxsu exo-open test.txt ; echo $?

0

Editor does not open.

Possible Solution

Steps to Reproduce (for bugs)

1. upgrade Debian stretch to Debian buster (in Qubes OS pr real Debian buster)
2. sudo apt-get install --no-install-recommends lxqt-sudo
3. touch test.txt
4. lxsu exo-open test.txt

Context

desktop shortcut using lxsu (to get root rights, to have a password prompt), followed by xdg-open (which is supposed to select the user's favorite chosen text editor rather than hardcoding any specific one [or inventing a custom mechanism for choosing one]).

System Information

• Distribution & Version: Debian buster (in Qubes)
• Kernel: Linux version 4.14.74-1.pvops.qubes.x86_64 (user@build-fedora4) (gcc version 6.4.1 20170727 (Red Hat 6.4.1-1) (GCC)) #1 SMP Mon Oct 8 17:14:24 UTC 2018
• Qt Version: libqt5designer5:amd64 5.11.3-4
• liblxqt Version: 0.14.1
• lxqt-build-tools Version: was build by Debian
• Package version: 0.14.1-1

exo-open comparison with non-root and sudo behavior

• touch test.txt
• works: exo-open test.txt
• works: sudo --set-home exo-open test.txt
• fails: lxsu exo-open test.txt
• fails in Qubes Debian buster as well as real Debian buster

env comparison with non-root and sudo behavior

Perhaps environment has something to do with it? I guess not. Just in case attaching the different output.

sudo --set-home env
COLORTERM=truecolor
XAUTHORITY=/home/user/.Xauthority
LANG=en_US.utf8
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.zst=01;31:*.tzst=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.wim=01;31:*.swm=01;31:*.dwm=01;31:*.esd=01;31:*.jpg=01;35:*.jpeg=01;35:*.mjpg=01;35:*.mjpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.oga=00;36:*.opus=00;36:*.spx=00;36:*.xspf=00;36:
TERM=xterm-256color
DISPLAY=:0.0
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
MAIL=/var/mail/root
LOGNAME=root
USER=root
HOME=/root
SHELL=/bin/bash
SUDO_COMMAND=/usr/bin/env
SUDO_USER=user
SUDO_UID=1000
SUDO_GID=1000

lxsu env

SHELL=/bin/bash
PWD=/home/user
XAUTHORITY=/home/user/.Xauthority
HOME=/root
LANG=en_US.UTF-8
DISPLAY=:0.0
SHLVL=0
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
MAIL=/var/mail/root

References

Also reported against exo-open:
https://bugzilla.xfce.org/show_bug.cgi?id=15282

[agaida]

try xdg-open - why should we support exo-open?

[tsujan]

why should we support exo-open?

That's a good question.

[adrelanos]

Please support exo-open since xdg-open uses it.

xdg-open runs exo-open in XFCE by default.

/usr/bin/xdg-open includes:

open_xfce()
{
    if exo-open --help 2>/dev/null 1>&2; then
        exo-open "$1"
    elif gio help open 2>/dev/null 1>&2; then
        gio open "$1"
    elif gvfs-open --help 2>/dev/null 1>&2; then
        gvfs-open "$1"
    else
        open_generic "$1"
    fi

    if [ $? -eq 0 ]; then
        exit_success
    else
        exit_failure_operation_failed
    fi
}

In case "$DE" in. Happens when environment variable XDG_CURRENT_DESKTOP is set to XFCE which is the default in Debian buster XFCE. xdg-open also sets DE to xfce in other cases.

[tsujan]

open_xfce() is for Xfce. xdg-open uses different functions under different DEs and supports LXQt. Supporting open_xfce() doesn't make sense.

[tsujan]

And you could always use gio open under LXQt if you prefer it. libfm-qt is based on GLib.

[adrelanos]

My mistake, I've been using lxqt-sudo in XFCE. I had wrongly assumed, that lxqt-sudo wants to be (a drop-in) replacement for the now deprecated gksudo / kdesudo (which are no longer available in Debian buster), being usable on any desktop environment.

People on the internet are discussing deprecation of gksudo / kdesudo and mentioning lxqt-sudo as an alternative in that context. So I guess others might make the same mistake as more people move to buster or other distributions with no more gksudo / kdesudo.

[palinek]

I don't see a reason why shouldn't it work with lxqt-sudo...
@adrelanos do you know internals of exo-open? Why doesn't it do its job when invoked in elevated environment by lxqt-sudo? Please, try to investigate the particular reason why is it failing (missing env var?) and then maybe we can do changes on our side to make it happy.

[agaida]

% lxsudo exo-open willi.txt
lxqt-sudo: Stripping child environment except for: DISPLAY, LANG, LANGUAGE, LC_ADDRESS, LC_ALL, LC_COLLATE, LC_CTYPE, LC_IDENTIFICATION, LC_MEASUREMENT, LC_MESSAGES, LC_MONETARY, LC_NAME, LC_NUMERIC, LC_PAPER, LC_TELEPHONE, LC_TIME, PATH, QT_PLATFORM_PLUGIN, QT_QPA_PLATFORMTHEME, WAYLAND_DISPLAY, XAUTHLOCALHOSTNAME, XAUTHORITY

(exo-open:26338): dbind-WARNING **: 09:48:20.201: Couldn't connect to accessibility bus: Failed to connect to socket /tmp/dbus-53SQZS2mi8: Verbindungsaufbau abgelehnt

The result is the same

(exo-open:12160): dbind-WARNING **: 09:52:21.960: Couldn't connect to accessibility bus: Failed to connect to socket /tmp/dbus-53SQZS2mi8: Verbindungsaufbau abgelehnt

[agaida]

@palinek - re-opened, if we can do something about the dbus issues we should do

[palinek]

I'm not getting the dbind-WARNING here...
But if I try to debug exo-open simply by lxqt-sudo strace -f exo-open ... then the desired application is launched as expected. This leads me to ask a question: Isn't there some race in exo-open implementation?

[palinek]

(sorry, missed the button)

[agaida]

ok, your guess might be right :)

[Iastonestanding]

The problem is reproducible with xdg-open after renaming exo-open (making it unavailable), and also with gio open.