Hello KDE devs and everyone who may read such bug reports or issue
requests,

I think I may have reported something similar before, in other KDE
widgets.

At any rate, my issue is with this error message here specifically:

    "The shared library was not found."

See the following picture:

    https://i.imgur.com/eoQa7r3.png

This is from systemsettings5, on a black KDE konsole background;
I chopped it up quickly to just show the problem. The problem
is on the right side: "The shared library was not found"

The URL I was using, just to provide this info as well, was 
this:

    https://download.kde.org/stable/plasma/5.19.5/systemsettings-5.19.5.tar.xz

I should add that I batch-compile all of KDE from source, so with
the today's release of a new plasma, I am compiling stuff again. So
I may have multiple different versions on the computer, since when
I am lazy, I just compile into /usr/ as the main prefix, even though
I also use a versioned AppDir layout sometimes (see GoboLinux for
this, such as /Programs/Htop/2.2.0 - do note that they have not
been able to keep up with KDE5 though. The last KDE release on
GoboLinux was KDE3.)

As a consequence of me compiling from source, on a modified 
slackware/zenwalk base system, I encounter some issues now and
then with KDE5 - not so much during compilation usually, but
lateron, such as when trying to start kwin from oldschool 
runlevel init 3, but also in using specific individual 
applications. Some work very well, such as KDE konsole or
okular; others work less well, or are a bit strange, such
as the systemsettings5 binary.

This feature request here is such an example for the "lateron"
problem - that is problems that show up when running the 
application at hand.

In regards to systemsettings5, some parts of this widget work
really fine, without problems, such as "Shortcuts". See the
above screenshot what is meant; that widget is shown
decently and it works.

"Window Behavior" also works fine - shows everything.

But other parts, such as "Display and Monitor", do not work,
and instead show a generic "The shared library was not found".

This message, as we can all agree, is almost TOTALLY useless.
Because it tells me NOTHING. I have to ask here: "what shared
library exactly was not found?". I mean, it is better than
nothing, but still quite useless. I assume that it refers to
some installed component that may be too old or not 
compatible, but I'd still like to know WHAT exactly is the
issue. As it is right now, the message "The shared library
was not found" is about as useful as "Aliens have taken 
over your computer and rendered it useless" - although one
could reasonably argue that that message is better than 
"The shared library was not found", because at the least
it identified SOME Aliens as being behind the culprit.
With systemsettings, though, we are currently left in the
dark.

I have noticed this, by the way, in other widgets too - 
in okular in the past, for example. So I assume that
this is more related in general to how KDE wants to 
present information to end users. I am fine if you
assume that the default end user is Average Joe, so you
may not want to burden him with too much information -
but then there should be an OPTIONAL way to query more 
information, and ideally in a per-widget or per-application
centric way because not everyone may use KDE5. I use
mostly individual KDE5 applications. (I'd use KDE5, but
I can not successfully start it, but this is a separate
issue not related to the issue request here. Note that
I can compile mate-desktop from source, and run it from
inittab runlevel 3 just fine. Some problems may also 
originate from qt5, such as qml-related problems, but
I don't want to make this issue request here too off-topic.
My primary point is for usability improvements and better
error reporting WITHIN KDE5/Plasma itself.)

On the commandline I may typically do "ldd" on some binary,
and if some shared object is missing, I tend to get some
message there, such as "missing /usr/lib/libtarzan.so"
or something like this. (Could be better too, but I 
digress here as well).

Anyway - I hope I could explain the use case leading to the
above issue request. What I would like to see here specifically
is that the error message "shared library" becomes MORE
SPECIFIC.

This can either happen in the same widget, such as:

   "The shared library liblala.so could not be found."

OR, if you don't want it in-widget, then perhaps a smallish button
could be shown, with "show more information about this error" or
"display more information about this error", or just "information
about this error" and/or a tooltip, or something like that, and
then in some small widget there, show a LOT more information.

This could then be used between many KDE applications, on an
per-option basis so that the individual author can decide
whether to use this or not. Not all widgets may need it, but
for something as fundamental as systemsettings5, I would
highly recommend it. (I actually wanted to change the font
size in KDE due to my bad eyesight. But since that widget 
does not seem to work, I think I will go with a ruby commandline
variant instead that simply modifies the file(s) that keep
this setting.)

This has been my problem with KDE5 in general by the way - the
software as it is is quite good and polished, when it works.

But until then it became quite a bit more complex, and
it sort of seems to cater more towards the big distributions
and Average Joe users; or perhaps more so than in the KDE3
days really. The big distributions may have the resources to
easily resolve any problems, whereas smaller distributions
and hobbyists don't quite have the same resources, e. g. in
the KDE3 days we had like 20 URLs to keep track of and now
we have like 400 or so if we include all of the KDE
applications too. I digress again, so back to the main TL;DR:

    Please improve the error messages in KDE5, in particular
    the "The shared library was not found" one.

PS: While I think that ideally this could be generalized,
and become "more useful error messages in all of KDE5",
I would prefer if it is still kept originally closely 
aligned towards systemsettings5. Otherwise I fear that it
may be moved between different individual components, and
3 years down the road it will be forgotten anyway because
nobody knows what happened with issue requests such as
this. :D

(I am not quite familiar how active KDE bugzilla still is;
I thought gitlab is the main reporting variant now, but
when I looked for where to file bugs, it all pointed to
https://bugs.kde.org so that was what I was using.)