解决 Ubuntu Linux 桌面无法打开应用的问题 - Debian/Ubuntu

最近我打开 .deb 和 .AppImage 包管理器的应用总是无法打开，使用命令行运行得到以下错误：

./bruno_3.5.2_x86_64_linux.AppImage
[254451:0715/135503.732123:FATAL:sandbox/linux/suid/client/setuid_sandbox_host.cc:169] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /tmp/.mount_bruno_uNgs19/chrome-sandbox is owned by root and has mode 4755.
[1]    254451 trace trap (core dumped)  ./bruno_3.5.2_x86_64_linux.AppImage

./bruno_3.5.2_x86_64_linux.AppImage
Preferences file is located at: /home/guodong/.config/bruno/preferences.json
Maximum number of clients reached
[276323:0715/140130.568089:ERROR:ui/ozone/platform/x11/ozone_platform_x11.cc:250] Missing X server or $DISPLAY
[276323:0715/140130.568134:ERROR:ui/aura/env.cc:257] The platform failed to initialize.  Exiting.
[1]    276323 segmentation fault (core dumped)  ./bruno_3.5.2_x86_64_linux.AppImage

错误 ”The SUID sandbox helper binary was found, but is not configured correctly. “是由于 AppArmor 阻止了，可以去创建一个配置文件 /etc/apparmor.d/bruno-AppImage 来允许。

# This profile allows everything and only exists to give the
# application a name instead of having the label "unconfined"
abi <abi/4.0>,
include <tunables/global>
profile bruno-AppImage /home/guodong/Downloads/bruno_3.5.2_x86_64_linux.AppImage flags=(unconfined) {
  userns,
  # Site-specific additions and overrides. See local/README for details.
  include if exists <local/bruno-AppImage>
}

错误“Maximum number of clients reached”，这个是我最近遇到比较多的。

这个错误并非每次都会遇到，例如刚登录系统时，这些冲突的应用都能正常打开，同时运行，但运行一段时间后，某个应用就无法打开了。由此可见确实是某些资源被占用了。

在这之前我也问过 AI，但是没有得到很好的解决。今天我用 Google 搜索，竟然得到了一个解决方法。

我搜索 “AppImage Maximum number of clients reached” 关键词，在 https://askubuntu.com/questions/681903/cannot-launch-apps-maximum-number-of-clients-reached 得到以下问答：

问：

Cannot launch apps - Maximum number of clients reached

Asked 10 years, 9 months ago Modified 2 years, 9 months ago Viewed 3k times

答：

in another thread, this helpt me!

sudo ss -x src "*/tmp/.X11-unix/*" | grep -Eo "[0-9]+\s*$" | while read port
do sudo ss -p -x | grep -w $port | grep -v X11-unix
done | grep -Eo '".+"' | sort | uniq -c | sort -rn

ss is a tool to investigate sockets
sudo ss -x src "*/tmp/.X11-unix/*" lists to calls that are binded to x11.
grep... Then grapping the number of port
while read port means take the given port number and feed it to...
sudo ss -p -x | grep -w $port | grep -v X11-unix done which will grep these port binded to x11 giving the name of the process, and then
sort | uniq -c | sort -rn sorting them in decreasing order based on how many exists in a given socket of system.

A simplified version which shows the first 10 processes that have open the most sockets to the system.

By knowing which process occupies the most sockets in the system, you can simply kill it. eg. killall process_name which will free sockets in your system to be used from other programs. The number of sockets in linux system are limited (but you can change its number - see links).

Related articles / bugs: here and here

于是，我执行了 sudo ss -x src "*/tmp/.X11-unix/*" | grep -Eo "[0-9]+\s*$" | while read port do sudo ss -p -x | grep -w $port | grep -v X11-unix done | grep -Eo '".+"' | sort | uniq -c | sort -rn，结果如下：

 234 "qq"
      5 "xuanxuan.bin"
      5 "WeChatAppEx"
      5 "termius-app"
      1 "wechat"
      1 "Snipaste"
      1 "mutter-x11-fram"
      1 "ibus-x11"
      1 "gsd-xsettings"
      1 "gnome-shell"

一共是 255 个(默认是255,好似不太容易调整)。我退出了 QQ 应用，发现确实可以正常打开其他应用了。

然后，我又启动了 QQ，重新执行了上面的命令，结果如下：

 6 "qq"
      5 "xuanxuan.bin"
      5 "WeChatAppEx"
      5 "termius-app"
      5 "bruno"
      1 "wechat"
      1 "Snipaste"
      1 "mutter-x11-fram"
      1 "ibus-x11"
      1 "gsd-xsettings"
      1 "gnome-shell"

有此可见，QQ 确实占用的比较多，应该是存在一些问题，这样后面就有办法处理了。

查看原始 X11 socket 列表：

sudo ss -x src "*/tmp/.X11-unix/*"

检查当前运行在图形界面上的客户端（list client applications running on a display）有哪些：

xlsclients -a