Debian removes FPC/Lazarus

[dbannon]

Did you look at https://wiki.freepascal.org/Qt5_Interface ?

Warning: linker: /usr/bin/ld: cannot find -lQt5Pas: No such file or directory
project1.lpr(27,1) Error: Error while linking

As the error message stated, the linker (ld) cannot find a library. Newer distributions just need to install libqt5pas-dev which brings in the Qt5 libraries (~50M in unlikely the extreme you have none installed, by comparison, gtk2 is about 200M).  I suggest you don't use Qt4. Qt6 may well be a better choice.

the machine that produced the above results is running Linux Mint 22.2 (XFCE) x86-64, supported until April 2029

Linux Mint 22.2 is based on Ubuntu 24.04 and therefore has up to date libqt5pas-dev. So, just install from your repo. Older systems may not have a suitable version of libq5pa-dev available, build them yourself or download from https://github.com/davidbannon/libqt5pas

Its worth noting that the term "supported" when applied to Linux Distros is often misunderstood. It does not mean that the distro has all the up to date software available, just some selected (by distro maintainers) packages, often just security. If its an old distro release, it has old software.

Davo

[vfclists]

[...] What /is/ relevant is that it would mandate a single set of interface objects with no opportunity for the IDE or programmer to work around them, and irrespective of how much work was put into it most people would find that their programs break

mark: i'm not sure i understand what you mean, can you please explain more?

do you mean that: currently a GUI application built for GTK2 'knows' that it is talking to GTK2 and can tweak things accordingly, likewise one built for Qt5 can do the same. but an application that has been built for both has no means (at the user-code level) of determining if it is talking to GTK2 or Qt5?

or do you mean that programmers building a GUI application that supported both GTK2 and Qt5 would need to put in extra effort to test every aspect of their program against both GTK2 and Qt5?

or do you mean something else?


from what dave wrote:
"Mode ?  Project->Options->Additions&Overrides.  Add a new build mode for every widget, then, in the grid line them up. Easy to see, hard to describe in words."
https://forum.lazarus.freepascal.org/index.php/topic,73405.msg576721.html#msg576721
... it sounds like i should be able to, with just a few clicks, generate ELF binaries for two or more widget sets. i followed his instructions, but unfortunately i get the following error message when compiling in the Lazarus IDE:

Warning: linker: /usr/bin/ld: cannot find -lQt5Pas: No such file or directory
project1.lpr(27,1) Error: Error while linking

... when selecting the 'Qt5' option, and when selecting the 'Qt' option:

Warning: linker: /usr/bin/ld: cannot find -lQt4Pas: No such file or directory
project1.lpr(27,1) Error: Error while linking

the machine that produced the above results is running Linux Mint 22.2 (XFCE) x86-64, supported until April 2029; all my other computers run similar configurations, although the machine i am typing on right now runs a rather old version 19.3.

how do i install Qt5 support? and/or Qt4 support? preferably in a way that does not break anything!

if i can easily produce multiple ELF binaries, each for a different widget set, then i already have available a relatively 'clean' solution to merge these into a single binary than can select between widget sets at startup.


cheers,
rob   :-)

https://github.com/davidbannon/libqt6pas

https://github.com/davidbannon/libqt5pas


libqt4pas is quite old but some distros have ready built packages for it.

https://wiki.lazarus.freepascal.org/Qt_Interface#Qt_4_Bindings

https://wiki.lazarus.freepascal.org/Qt5_Interface

Some distros have ready made packages for it.


Another thing you have to remember is that when you compile LCL libraries, you have to adjust the output paths for the packages to include widgetset, OS, and architecture or else you will be in a whole world of pain as you switch between the widgetsets.

PS. I see @dbannon responded as I was composing this reply. His answer may be more authoritative.

[robert rozee]

am deviating further off topic i fear...

just installing the following worked:
sudo apt install libqt5pas-dev

for the project i then tested (around 5000 lines of code), the only code change i needed to make was in one place where i had a TLabel that had multiple lines of text being assigned to it, with lines separated by carriage returns. i needed to change the carriage returns to carriage return + line feed, as just carriage returns alone were ignored by Qt5.


however, i couldn't figure out any simple apt install for Qt6, and this page: https://wiki.freepascal.org/Qt6_Interface#Linux suggests that Qt6 is not entirely bug-free.

does Qt6 provide backward compatibility with Qt5? ie, will a machine with Qt6 on it be likely to also have Qt5 present, or a Qt5 'compatibility layer'?

another question - at the moment, if i give someone an ELF binary built for GTK2 they can (based on feedback i've received) just run it without any problems - they do not need to install anything else. does the same hold for an ELF binary i've built for Qt5? or do i also need to have them install libqt5pas.so? or is libqt5pas.so always present in distros that out-of-the-box have Qt5 installed?


and lastly - how do i configure the Lazarus IDE to build multiple ELF binaries using different widget sets, without my needing to go into Project -> Options and change build mode manually? can one build mode be set up to do this? if i set up two lines in a mode, with both 'ticked', it only seems to use one of them (see below image).

ideally, i'd like to be able to have, for example, building Project1 to produce two ELF images called Project1.GTK2 and Project1.Qt5. is this possible?


cheers,
rob   :-)

[Thaddy]

Don't use Qt5, use Qt6. (Djeez, bad advice again Robert)
Otherwise you are again on the backfoot by installing/migrating to something that is too old in the general perspective of things.
Use Qt6. That's the thing that avoids your Wayland issues.

Use Qt6, Use Qt6, Use Qt6. Stop promoting anything else.
All experts agree about that. The rest is either too old on its own (GTK3) or does not work well with Wayland (Qt5)

Feel free to use anything else of course, but than you are stuck with legacy or soon to be legacy.
You may examine the list of software that Debian actually removes and that list is quite long, not just Lazarus/fpc. It is the longest list of removals I have seen yet with Debian.

[wp]

Use Qt6. That's the thing that avoids your Wayland issues.

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

[dsiders]

Use Qt6. That's the thing that avoids your Wayland issues.

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

A perfect example of a protocol designed by a committee that performs no implementations.

[sfeinst]

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

Same issue with Debian Trixie.  To get around that, I installed anchordockingdsgn (which I never use normally) to get around all the centered IDE windows.

[Thaddy]

Use Qt6. That's the thing that avoids your Wayland issues.

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

Did not test KDE desktop, only trixies default.

[zeljko]

Use Qt6. That's the thing that avoids your Wayland issues.

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

No joking. That's default wayland behaviour. KDE is doing some changes in that direction (remember postitions) , but setting position of window is no-no in wayland, and it'll probably never work. So I can see all your windows centered - exactly what wayland does. Try to use docked ide (even that have problems with wayland).

[dsiders]

Use Qt6. That's the thing that avoids your Wayland issues.

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

No joking. That's default wayland behaviour. KDE is doing some changes in that direction (remember postitions) , but setting position of window is no-no in wayland, and it'll probably never work. So I can see all your windows centered - exactly what wayland does. Try to use docked ide (even that have problems with wayland).

Everyone keeps repeating this... but no one seems to read or understand it.
DON'T USE WAYLAND. IT'S BRAIN-DEAD.
If your favorite distro forces you to use it... it's time to move on to another distro.

[dbannon]

Everyone keeps repeating this... but no one seems to read or understand it.
DON'T USE WAYLAND. IT'S BRAIN-DEAD.
If your favorite distro forces you to use it... it's time to move on to another distro.

While I agree absolutely with the sentiment, the fact is that its already hard to avoid Wayland, and becoming more so. Firstly, Wayland is not a "distro by distro" decision, its a desktop thing. For example, Trixie Debian, if you install/use Gnome or KDE, you get Wayland. If you install, same disto, Mate Desktop, you get X11.

Xfce has committed to a totally Wayland model, Enlightenment was an early Wayland convert. I don't know about Cinnamon, Budgie etc. 

Over time, Distros will want to simplify their repos so, pressure is on the Desktops to "comply". They will almost certainly do so. The FPC/Lazarus community can choose to ignore Wayland but that will not do us any good at all, its happening.

Davo

[dsiders]

Everyone keeps repeating this... but no one seems to read or understand it.
DON'T USE WAYLAND. IT'S BRAIN-DEAD.
If your favorite distro forces you to use it... it's time to move on to another distro.

While I agree absolutely with the sentiment, the fact is that its already hard to avoid Wayland, and becoming more so. Firstly, Wayland is not a "distro by distro" decision, its a desktop thing. For example, Trixie Debian, if you install/use Gnome or KDE, you get Wayland. If you install, same disto, Mate Desktop, you get X11.

OK, what I should had written is "if your favorite WM/DE...". It doesn't change the fact that distros are in fact dropping X11 by default... and both the distros and the desktops are shooting themselves in the foot.

Xfce has committed to a totally Wayland model, ...

Good for them. I can now conveniently ignore them too.

Enlightenment was an early Wayland convert.

I bet both of its users are entirely happy too.

I don't know about Cinnamon, Budgie etc. 

Do they have users? Seriously, who cares?

Over time, Distros will want to simplify their repos so, pressure is on the Desktops to "comply". They will almost certainly do so. The FPC/Lazarus community can choose to ignore Wayland but that will not do us any good at all, its happening.

Ok, let's ratchet up our anxiety level and fret. What can Lazarus do about Wayland being brain-dead? Nothing. Ignore it until the time that they:

A) Admit they were stupid and fucked up royally.
B) Have fixed it.

I have pretty much the same outlook on this Debian drops Lazarus hysteria. Let's suppose they do it... does that mean Debian users cannot install Lazarus? No, it does not. Does it mean that the Debian nonsense about repos goes away? I hope so... and YEAH.

[cdbc]

Hi
AFAIK @Graeme is __not__ in a hurry, to jump on the 'Wayland Bus' anytime soon  I'm wholeheartedly exploring 'fpGUI' ...and having fun doing it  at the moment -- I guess that's my path forward.
Just my 2 cents worth
N.b.: I do love my Qt6, though, but atst. I'm also exploring 'IceWM' 
Regards Benny

[PascalDragon]

Use Qt6. That's the thing that avoids your Wayland issues.

Joking? This is a screenshot taken from Laz/QT6 on Majaro KDE/wayland.

That's not a fault of Qt and GTK would behave the same, because Wayland did not provide a way to specify positions until a few weeks ago and even then it's only part of the protocols for now, so essentially no released compositor and no released framework supports it.

No joking. That's default wayland behaviour. KDE is doing some changes in that direction (remember postitions) , but setting position of window is no-no in wayland, and it'll probably never work. So I can see all your windows centered - exactly what wayland does.

As said above, initial positioning is the point of the xx-zones protocol. And remembering positions is supposed to be handled by the yet-to-be-merged session restore protocol.

[zeljko]

+ current distros probably will never update to such wayland addons (eg KDE Plasma 6.6).