[konsole] [Bug 507216] New: Konsole fails if I open 300 windows with "QProcess: Cannot create pipe (Too many open files)"; please, raise RLIMIT_NOFILE

[Tomaz Canabrava]

but why woyld anyone keep 300 konsole windows open?
i honestly dont think this is a bug.


On Sat, 19 Jul 2025 at 07:43 Askar Safin <bugzilla_noreply at kde.org> wrote:

> https://bugs.kde.org/show_bug.cgi?id=507216
>
>             Bug ID: 507216
>            Summary: Konsole fails if I open 300 windows with "QProcess:
>                     Cannot create pipe (Too many open files)"; please,
>                     raise RLIMIT_NOFILE
>     Classification: Applications
>            Product: konsole
>       Version First 25.04.2
>        Reported In:
>           Platform: Debian testing
>                 OS: Linux
>             Status: REPORTED
>           Severity: normal
>           Priority: NOR
>          Component: single-process
>           Assignee: konsole-devel at kde.org
>           Reporter: safinaskar at mail.ru
>   Target Milestone: ---
>
> SUMMARY
> Konsole fails if I open 300 windows with "QProcess: Cannot create pipe (Too
> many open files)"
>
> STEPS TO REPRODUCE
> Try to open 300 Konsole windows
>
> OBSERVED RESULT
> All windows close on its own
>
> EXPECTED RESULT
> Windows should not close on its own
>
> SOFTWARE/OS VERSIONS
> Linux/KDE Plasma: Debian Trixie 13, x86_64
> uname -a: Linux comp 6.12.35+deb13-amd64 #1 SMP PREEMPT_DYNAMIC Debian
> 6.12.35-1 (2025-07-03) x86_64 GNU/Linux
> KDE Plasma Version: 6.3.5
> KDE Frameworks Version: 6.13.0
> Qt Version: 6.8.2
> Konsole version: 25.04.2
> Wayland
>
> ADDITIONAL INFORMATION
> "journalctl" shows this:
>
> Jul 19 07:41:26 comp konsole[2187]: org.kde.konsole: foregroundProcessGroup
> master_fd < 0
> Jul 19 07:41:26 comp konsole[2187]: QLayout: Cannot add a null widget to
> QHBoxLayout/
> Jul 19 07:41:26 comp konsole[2187]: kf.pty: Can't open a pseudo teletype
> Jul 19 07:41:26 comp konsole[2187]: org.kde.konsole: foregroundProcessGroup
> master_fd < 0
> Jul 19 07:41:26 comp konsole[2187]: QProcess: Cannot create pipe (Too many
> open
> files)
> Jul 19 07:41:26 comp konsole[2187]: QProcess: Cannot create pipe (Too many
> open
> files)
> Jul 19 07:41:26 comp konsole[2187]: QLayout: Cannot add a null widget to
> QHBoxLayout/
> Jul 19 07:41:27 comp konsole[2187]: kf.pty: Can't open a pseudo teletype
> Jul 19 07:41:27 comp konsole[2187]: org.kde.konsole: foregroundProcessGroup
> master_fd < 0
> Jul 19 07:41:27 comp konsole[2187]: QProcess: Cannot create pipe (Too many
> open
> files)
> Jul 19 07:41:27 comp konsole[2187]: QProcess: Cannot create pipe (Too many
> open
> files)
> Jul 19 07:41:27 comp konsole[2187]: QLayout: Cannot add a null widget to
> QHBoxLayout/
> Jul 19 07:41:27 comp konsole[2187]: kf.pty: Can't open a pseudo teletype
> Jul 19 07:41:27 comp konsole[2187]: org.kde.konsole: foregroundProcessGroup
> master_fd < 0
> Jul 19 07:41:27 comp konsole[2187]: QLayout: Cannot add a null widget to
> QHBoxLayout/
> Jul 19 07:41:27 comp konsole[2187]: kf.pty: Can't open a pseudo teletype
> Jul 19 07:41:27 comp konsole[2187]: org.kde.konsole: foregroundProcessGroup
> master_fd < 0
> Jul 19 07:41:27 comp konsole[2187]: The Wayland connection experienced a
> fatal
> error: Too many open files
> Jul 19 07:41:27 comp konsole[4941]: QLayout: Cannot add a null widget to
> QHBoxLayout/
> Jul 19 07:41:27 comp systemd[1371]:
> app-org.kde.konsole at 282b2f16ea744533bf654a1f827f5aad.service: Main process
> exited, code=exited, status=255/EXCEPTION
> Jul 19 07:41:27 comp systemd[1371]:
> app-org.kde.konsole at 282b2f16ea744533bf654a1f827f5aad.service: Failed with
> result 'exit-code'.
> Jul 19 07:41:27 comp systemd[1371]:
> app-org.kde.konsole at 282b2f16ea744533bf654a1f827f5aad.service: Consumed
> 314ms
> CPU time, 130.2M memory peak.
> Jul 19 07:41:27 comp systemd[1371]: app-org.kde.konsole-2187.scope:
> Consumed
> 42.811s CPU time, 11.8G memory peak.
>
> So, it seems Konsole opens too many files.
>
> I added DefaultLimitNOFILE=524288:524288 to /etc/systemd/user.conf and
> /etc/systemd/system.conf .
> And the bug disappeared.
> So I suggest to follow advice in this Poettering blog
> https://0pointer.net/blog/file-descriptor-limits.html and to raise
> RLIMIT_NOFILE at startup.
> Possibly this change should be propagated to all KDE apps or even to all Qt
> apps
>
> --
> You are receiving this mail because:
> You are the assignee for the bug.
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