From Newsgroup: alt.os.linux.fedora

I upgraded my Fedora 42 installation with dnf upgrade (all packages with
a newer version available), and after that I can't start seamonkey or brave-browser.
Before those updates, both worked fine.

If I try starting seamonkey from Konsole window, it says
Error: no DISPLAY environment variable specified
brave-browser responds with [52291:52291:0801/012124.252370:ERROR:ui/ozone/platform/x11/ozone_platform_x11.cc:249] Missing X server or $DISPLAY

Using a search engine, I found a hint suggesting to set the DISPLAY
variable with
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print
$2; exit;}'):0.0
and another one suggesting
export DISPLAY=unix:0.0

Neither of those helped.
With the latter setting, brave-browser gives the same error message as
before, seamonkey says
Error: cannot open display: unix:0.0

The last makes me think there may be a permission problem somewhere, but
I can't guess where it is and what I should do to fix it (except waiting
for the next upgrade packages..)

I run my system on runlevel 3, logging in to a tty console and starting
kde with the command startplasma-wayland
--
Jukka Lahtinen
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From Newsgroup: alt.os.linux.fedora

On 2025-07-31, Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> wrote:

Using a search engine, I found a hint suggesting to set the DISPLAY
variable with
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print
$2; exit;}'):0.0
and another one suggesting
export DISPLAY=unix:0.0

Neither of those helped.
With the latter setting, brave-browser gives the same error message as before, seamonkey says
Error: cannot open display: unix:0.0

I use GNOME, not KDE, and have not had such a problem.
But when I oipen a terminal window to display the DISPLAY environment
variable, the value is just ":0"

So try " export DISPLAY=:0 "

What goes before the colon is a host name. Normally, that would be
"localhost" (127.0.0.1), but I believe that is the default if none is
given. But that should have been set when wayland started and inherited
by everything in the process tree below.

Of course, the terminal window from which you started KDE and wayland in
the first place is not running under the GUI, so if you try to start a
GUI application from there, it will not work, and you might get exactly
what you describe.
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From Newsgroup: alt.os.linux.fedora

Lars Poulsen <lars@cleo.beagle-ears.com> writes:

On 2025-07-31, Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> wrote:

Using a search engine, I found a hint suggesting to set the DISPLAY
variable with
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print
$2; exit;}'):0.0
and another one suggesting
export DISPLAY=unix:0.0

Neither of those helped.
With the latter setting, brave-browser gives the same error message as
before, seamonkey says
Error: cannot open display: unix:0.0

I use GNOME, not KDE, and have not had such a problem.
But when I oipen a terminal window to display the DISPLAY environment variable, the value is just ":0"

So try " export DISPLAY=:0 "

That didn't help either. Error message from seamonkey was
Error: cannot open display: :0
I think I already tried that too, but forgot to mention.

What goes before the colon is a host name. Normally, that would be "localhost" (127.0.0.1), but I believe that is the default if none is
given. But that should have been set when wayland started and inherited
by everything in the process tree below.

Funny, my /etc/resolv.conf has the line
nameserver 127.0.0.53
so that's what the first fix suggestion I found ended up using.
Anyway, setting DISPLAY to 127.0.0.1:0 didn't help either.

Of course, the terminal window from which you started KDE and wayland in
the first place is not running under the GUI, so if you try to start a
GUI application from there, it will not work, and you might get exactly
what you describe.

I didn't start KDE from a terminal WINDOW, but a fullscreen virtual
terminal, tty.
There were no windows before starting the gui.
Trying to start seamonkey or brave from a window in kde gui is how I got
the error messages I mentioned. The desktop icons didn't display any
messages, so I tried starting them from a Konsole window.

Both browsers worked fine before installing this week's upgrade packages.
--
Jukka Lahtinen
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: alt.os.linux.fedora

Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> writes:

Lars Poulsen <lars@cleo.beagle-ears.com> writes:

On 2025-07-31, Jukka Lahtinen <jtfjdehf@hotmail.com.invalid> wrote:

Using a search engine, I found a hint suggesting to set the DISPLAY
variable with
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print
$2; exit;}'):0.0
and another one suggesting
export DISPLAY=unix:0.0

Neither of those helped.

I use GNOME, not KDE, and have not had such a problem.
But when I oipen a terminal window to display the DISPLAY environment
variable, the value is just ":0"
So try " export DISPLAY=:0 "

That didn't help either. Error message from seamonkey was
Error: cannot open display: :0

I also tried exiting kde and restarting it, and that didn't help.
But when I rebooted the system, both seamonkey and brave work again, so
the problem seems to have disappeared.
And now, in a Konsole window, echo $DISPLAY shows
:0
--
Jukka Lahtinen
--- Synchronet 3.21a-Linux NewsLink 1.2