# Ann: SWI-Prolog 9.3.26 **URL:** \ **Category:** Releases\ **Created:** [July 23, 2025, 3:50pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120 "2025-07-23T15:50:15Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 23, 2025, 3:50pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/1 "2025-07-23T15:50:15Z")
Dear SWI-Prolog user, I have uploaded SWI-Prolog 9.3.26. From the Prolog point of view, this merely fixes a few minor issues. As discussed though, the tooling has changed considerably: - The xpce GUI toolkit is now based on the SDL3+Cairo+Pango libraries, using practically the same source on all platforms. - The GUI toolkit now runs natively on MacOS (i.e., no more need for XQuartz) and Wayland (the Linux display server that is now more and more replacing X11). - The `swipl-win` executable now uses xpce for its console window. This implies that the native `swipl-win.exe` on Windows and the Qt based version for MacOS and Linux have gone. - The GNU readline binding is disabled. We now use the BSD libedit for command line editing as it is more flexible and can support more instances, which allows it to run inside the xpce based Prolog console(s). Availability - As usual, we provide binaries for Windows and MacOS. These use the full stack outlined above. - We will update the flatpak version. The snap version will be discontinued as it is harder to manage and serves the same purpose as the flatpak version. - We provide PPAs for Ubuntu. The one for plucky (25.04) will provide the gui. Versions for older Ubuntu releases will not. Users can either use the flatpak version or build from source, after building SDL3 and SDL3\_image from source. Unfortunately the plucky PPA build failed to include the gui as well. This will be fixed. - The Macports version will be updated. Unfortunately there is an issue with Macports SDL3\_image package that prevents `port` from building it. You can build SWI-Prolog using the dependencies from Macports, including SDL3\_image. This is merely an issue on how `port` works. Issues are to be expected and a quick re-release as well. Please test! ``` Enjoy --- Jan ``` # SWI-Prolog Changelog since version 9.3.25 - FIXED: `swipl-win` installation for MacOS when not creating a bundle. - PPA: Updated scripts/make-ppa to setup building without gui for older distros - ADDED: Empty `light` theme file. - FIXED: Code generation for unification moved to the head. Minimal test case: `p(X, Y) :- X = f(Y), Y = a.`. Issue occurs if a variable is accessed (Y) before its unification must be moved to the head. - FIXED: Building; typo in prolog\_pack/http fix - BUILD: Avoid installing some libraries with missing dependencies - Do not install library(prolog\_pack) if http support is missing. - FIXED: library(prolog\_xref): added some missing hook declarations. - THEME: Dark theme declarations for class list\_browser and the profiler. Requires the SDL version of xpce. - ENHANCED: Improve `dark` theme Only applies with new SDL based xpce - PORT: Fixed MacOS installer to include transitive dependencies and fix the @rpath. - BUILD: Fixed PGO build with `-DEPILOG=ON` - BUILD: Ensure proper GUI environment for building the manual. - ADDED: Support `-Dtheme=` - PORT: Update scripts/macos-deps.sh Update most ports, add SDL3, SDL3\_image, cairo and pango. - ADDED: Working directory handling for MacOS app. - PORT: Create a MacOS bundle based on Epilog. - ENHANCED: interactor/0,1: use epilog when available. In the long term we will drop xterm support as well as native win32 support. - EPILOG: Deal with `--win-app` option in a way that also supports epilog. - ENHANCED: Remove thread context for threads running the REPL loop. This avoids the complicating `[Thread xyz]` note on messages in alternate consoles such as Epilog or SSH shells. - ADDED: Prolog flag `toplevel_thread`. This flag is `true` in a thread that is currently running a REPL loop. - FIXED: Edit from PceEmacs using popup could raise an error. E.g. ERROR: prolog\_edit:is\_file\_spec/1: No rule matches prolog\_edit:is\_file\_spec(20\_625\_830) - BUILD: Add CMake `-DEPILOG` option This option prepares the core for the upcoming Epilog configuration. It must be used with the `sdl` branch of `packages/xpce`. Effect: - PORT: Find MinGW DLL dependencies more dynamically This provides two CMake functions to find the direct and indirect MinGW DLLs that must be included into the distribution - ADDED: Allow storing the tty screen size with a stream. This is required for environments where we use a non-tty I/O device such as a pipe or socket while there is a notion of a tty size. Currently used for Epilog on Windows. - MODIFIED: print\_term/2: print dict tags and compound functors using the current write options. Both used to be printed hardwired using `~q` (quoted). - FIXED: When `rational_syntax` is `natural`, write /(Int,Number) with spaces. This ensures such a term is not read as a rational number. - FIXED: Use autoload\_call/1 to avoid reporting undefined predicates. - MODIFIED: Make the code walker ignore calls to autoload\_call/1. - ADDED: autoload\_call/1: call Goal after autoloading. - PORT: Avoid errors on sharing violations. - FIXED: Windows: comparing string equality with surrogate pairs Comparing strings with surrogate pairs could signal inequality while the strings are equal. - FIXED: Unification to chars or codes of wchar\_t text on Windows. ## Package debian - PPA: Updated to support xpce based GUI This deletes the Qt console (swi-prolog-win package) and replaces the X11 dependencies with SDL+cairo+pango. ## Package libedit - ADDED: Support winlibedit hook to get the terminal size. This allows fetching the terminal size for Epilog on Windows. - PORT: Make el\_history\_events/2 also work on the fileno property on Windows. - ENHANCED: Use autoload\_call/1 to avoid undefined errors. - FIXED: Read multi-byte characters on non-Windows. - ADDED: Support Windows pipe handles for I/O This is work in progress to support Epilog on Windows. It consists of changes to our winlibedit port of libedit. These changes do not use Console mode setting and read using ReadFile() rather than ReadConsoleInput(). ## Package xpce - See at the top ---
**Author:** ![peter.ludemann](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/peter.ludemann/32/48_2.png) [@peter.ludemann](https://swi-prolog.discourse.group/u/peter.ludemann)\ **Post date:** [July 23, 2025, 8:22pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/2 "2025-07-23T20:22:17Z")
Oops … my mistake when building SDL … deleted my error report. ---
**Author:** ![mike.elston](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/mike.elston/32/3691_2.png) [@mike.elston](https://swi-prolog.discourse.group/u/mike.elston)\ **Post date:** [July 23, 2025, 11:23pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/3 "2025-07-23T23:23:34Z")
Hi Jan I tried building from source. First built SDL3 and SDL\_image: $ lsb\_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 24.04.2 LTS Release: 24.04 Codename: noble SDL3 git clone [GitHub - libsdl-org/SDL: Simple Directmedia Layer](https://github.com/libsdl-org/SDL.git) cd SDL ls -al cmake --version g++ --version mkdir build cd build cmake .. ls make -j 8 sudo make install No errors or warnings SDL\_image git clone [GitHub - libsdl-org/SDL\_image: Image decoding for many popular formats for Simple Directmedia Layer.](https://github.com/libsdl-org/SDL_image.git) cd SDL\_image mkdir build cd build cmake .. make sudo make install No errors or warnings SWIPL cd swipl-devel/ 2030 git clean -xfd 2031 git submodule foreach git clean -xfd 2032 git pull 2033 git submodule update --init 2034 mkdir build 2035 cd build 2036 cmake -DCMAKE\_INSTALL\_PREFIX=$HOME -DCMAKE\_BUILD\_TYPE=PGO -G Ninja .. – signal handler is not reset (BSD signals) – Check size of double CMake Error at /home/mike/swipl-devel/build/CMakeFiles/CMakeScratch/TryCompile-nQX4Dk/CMakeLists.txt:30 (target\_link\_libraries): Target “cmTC\_c07a3” links to: ``` SDL3::SDL3 ``` but the target was not found. Possible reasons include: ``` * There is a typo in the target name. * A find_package call is missing for an IMPORTED target. * An ALIAS target is missing. ``` CMake Error at /usr/share/cmake-3.28/Modules/CheckTypeSize.cmake:146 (try\_compile): Failed to generate test project build system. Call Stack (most recent call first): /usr/share/cmake-3.28/Modules/CheckTypeSize.cmake:271 (\_\_check\_type\_size\_impl) packages/xpce/cmake/XPCEConfig.cmake:13 (check\_type\_size) packages/xpce/CMakeLists.txt:33 (include) ---
**Author:** ![peter.ludemann](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/peter.ludemann/32/48_2.png) [@peter.ludemann](https://swi-prolog.discourse.group/u/peter.ludemann)\ **Post date:** [July 24, 2025, 12:56am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/4 "2025-07-24T00:56:28Z")
I got the same error on Debian 12 (bookworm): ```txt CMake Error at /home/peter/src/swipl-devel/build.debug/CMakeFiles/CMakeScratch/TryCompile-0dljyG/CMakeLists.txt:26 (target_link_libraries): Target "cmTC_8a416" links to: SDL3::SDL3 but the target was not found. Possible reasons include: * There is a typo in the target name. * A find_package call is missing for an IMPORTED target. * An ALIAS target is missing. CMake Error at /usr/share/cmake-3.25/Modules/CheckIncludeFile.cmake:95 (try_compile): Failed to generate test project build system. Call Stack (most recent call first): cmake/Utils.cmake:45 (check_include_file) packages/xpce/cmake/XPCEConfig.cmake:16 (AC_CHECK_HEADERS) packages/xpce/CMakeLists.txt:33 (include) ``` I built with options from Jan’s config file, but with static and test turned on (the ctest for SDL had 2 failed tests: `testautomation`, `testautomation-no-simd`, which I presume don’t matter). I also got a warning from cmake: `Could NOT find ALSA (missing: ALSA_LIBRARY ALSA_INCLUDE_DIR) `. These were the commands I used to build SDL and SDL\_image: ```txt git clone --recurse git@github.com:libsdl-org/SDL.git git clone --recurse git@github.com:libsdl-org/SDL_image.git cd ~/src/SDL && mkdir -p build && cd build cmake -G Ninja -DSDL_SHARED=ON -DSDL_STATIC=ON -DSDL_TESTS=ON .. ninja && ctest -j6 && sudo ninja install cd ~/src/SDL_image && mkdir -p build && cd build cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -DSDLIMAGE_BACKEND_IMAGEIO=ON -DSDLIMAGE_BACKEND_STB=ON -DSDLIMAGE_JPG=ON -DSDLIMAGE_PNG=ON -DSDLIMAGE_WEBP=OFF .. ninja && sudo ninja install ``` ---
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 24, 2025, 9:44am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/5 "2025-07-24T09:44:09Z")
> [@mike.elston](#): > > CMake Error at /home/mike/swipl-devel/build/CMakeFiles/CMakeScratch/TryCompile-nQX4Dk/CMakeLists.txt:30 (target\_link\_libraries): > Target “cmTC\_c07a3” links to: > > `SDL3::SDL3` Also by @peter.ludemann . This is an issue with older versions of cmake. I stumbled on it at some point as well and fixed it by updating CMake. ChatGPT proposes another solution that makes the configuration work with older versions. Please **do reconfigure from scratch**. I pushed fixes for this. There are also some other small fixes for benign compiler warnings and QLF compilation warnings if the build locale is not UTF-8 based. Also pushed fixes for two bad colours in the dark theme. All now compiles completely clean on Debian Bookworm for me (started from a clean Docker image). Thanks for the feedback. ---
**Author:** ![mike.elston](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/mike.elston/32/3691_2.png) [@mike.elston](https://swi-prolog.discourse.group/u/mike.elston)\ **Post date:** [July 24, 2025, 10:44am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/6 "2025-07-24T10:44:42Z")
Thanks Jan. Got much futher but then this: 2490/2691] Generating lib/main.tex SDL\_Init() failed: No available video device SDL\_VIDEODRIVER=(null) [PCE fatal: nil: Failed to initialize SDL in: ] Host stack: [96] pce\_principal:set\_pce\_thread([app\_name(swipl)]) [94] ‘$run\_init\_goal’(pce:start\_dispatch) [93] catch(system:‘$run\_init\_goal’(pce:start\_dispatch), \_132890, system:‘$initialization\_error’(\_132890, pce:start\_dispatch, ‘/home/mike/swipl-devel/build/home/xpce/prolog/lib/pce.pl’:179)) [92] catch\_with\_backtrace(system:‘$run\_init\_goal’(pce:start\_dispatch), \_132890, system:‘$initialization\_error’(\_132890, pce:start\_dispatch, ‘/home/mike/swipl-devel/build/home/xpce/prolog/lib/pce.pl’:179)) [91] ‘$run\_init\_goal’(pce:start\_dispatch, ‘/home/mike/swipl-devel/build/home/xpce/prolog/lib/pce.pl’:179) [2576/2691] Generating HTML documentation for core system FAILED: man/manual.html /home/mike/swipl-devel/build/man/manual.html cd /home/mike/swipl-devel/build/man && rm -f Manual/_.html Manual/_.gif && /usr/bin/cmake -E env --unset=DISPLAY SDL\_VIDEODRIVER=dummy /home/mike/swipl-devel/build/src/swipl -f none --no-packs /home/mike/swipl-devel/build/home/library/ext/ltx2htm/latex2html.pl – --quiet --texinputs=lib:: SWI-Prolog-9.3.26 && /usr/bin/cmake -E remove /home/mike/swipl-devel/build/home/doc/manindex.db && /usr/bin/cmake -E touch manual.html ERROR: [Thread main] /home/mike/swipl-devel/build/home/library/ext/ltx2htm/latex2html.pl:3224: tex:main source\_sink `tex(main)’ does not exist [2585/2691] Generating tests/test\_certs/generated ninja: build stopped: subcommand failed. ---
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 24, 2025, 11:25am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/7 "2025-07-24T11:25:12Z")
Hmm. Weird. There is the `/usr/bin/cmake -E env --unset=DISPLAY SDL_VIDEODRIVER=dummy` but that doesn’t seem to get through. I noticed that before in some build environment. The simple work-around is to do `export SDL_VIDEODRIVER=dummy` before running ninja. You don’t have to start again. Just set the variable and re-run ninja. The the only question remaining is why … In what environment are you building? ---
**Author:** ![mike.elston](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/mike.elston/32/3691_2.png) [@mike.elston](https://swi-prolog.discourse.group/u/mike.elston)\ **Post date:** [July 24, 2025, 11:36am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/8 "2025-07-24T11:36:02Z")
$ lsb\_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 24.04.2 LTS Release: 24.04 Codename: noble ---
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 24, 2025, 11:56am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/9 "2025-07-24T11:56:56Z")
> [@mike.elston](#): > > $ lsb\_release -a Thanks. Did you build in the GUI environment, i.e., can you start X11/Wayland tools from the shell in which you were building? A great thing about SDL is that there is the dummy driver that allows the library to function without a GUI, but apparently the setting doesn’t come through ☹ ---
**Author:** ![peter.ludemann](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/peter.ludemann/32/48_2.png) [@peter.ludemann](https://swi-prolog.discourse.group/u/peter.ludemann)\ **Post date:** [July 24, 2025, 9:39pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/10 "2025-07-24T21:39:48Z")
> [@jan](#): > > work-around is to do `export SDL_VIDEODRIVER=dummy` before running ninja I did this and it built fine. I tried gtrace/0 and edit/0, and they worked as expected, except I had to change `~/.config/swi-prolog/xpce/Defaults`: ```prolog font.scale: @display?dpi?width/200 ``` (I was using width/150 before) ```txt $ lsb_release -a && uname -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 12 (bookworm) Release: 12 Codename: bookworm Linux penguin 6.6.76-08024-gb30cb4a129c2 #1 SMP PREEMPT_DYNAMIC Fri, 25 Apr 2025 05:08:33 -0700 x86_64 GNU/Linux ``` ---
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 25, 2025, 7:03am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/11 "2025-07-25T07:03:39Z")
> [@peter.ludemann](#): > > worked as expected Fine > [@peter.ludemann](#): > > `font.scale: @display?dpi?width/200` You can just use a constant. `@display?dpi` is bogus as SDL does not report that. It is fixed to 96. SDL uses logical pixels that should be treated as old style low-res displays. SDL, Cairo and Pango all deal with sub-pixel resolutions (each in their own way …) and parts of xpce now handle dimensions as floats. ---
**Author:** ![peter.ludemann](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/peter.ludemann/32/48_2.png) [@peter.ludemann](https://swi-prolog.discourse.group/u/peter.ludemann)\ **Post date:** [July 25, 2025, 11:17pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/12 "2025-07-25T23:17:24Z")
> [@jan](#): > > `@display?dpi` is bogus as SDL does not report that. It is fixed to 96. So, is this what I should have in `Defaults` file?: ```txt display.dpi: 96 font.scale: 1.0 ``` BTW, ctrl-C (from my terminal) with gtrace doesn’t behave the way I remember it … it seems to get stuck. And when closing the trace window, “Exit from Prolog” simply returns to the SWI-Prolog REPL. ---
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 26, 2025, 10:50am UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/13 "2025-07-26T10:50:21Z")
> [@peter.ludemann](#): > > So, is this what I should have in `Defaults` file?: > > ```prolog > display.dpi: 96 > font.scale: 1.0 > > ``` I would not say anything about DPI. Just use font.scale. The default is 1.0. Depending on your preferences and hardware it seems to end up between 0.8 and 1.2 or so to get what you want. If that is true for all of us, we are fine. > [@peter.ludemann](#): > > BTW, ctrl-C (from my terminal) with gtrace doesn’t behave the way I remember it … it seems to get stuck. Yes. That happens if you are waiting for the tracer gui. That is because the GUI now runs in the main thread as that seems to be required on most platforms SDL supports. But, if it is waiting for the tracer you can use ‘a’ to abort. If it is not waiting for the tracer (i.e., you do a _leap_ and no spy point gets hit), Ctrl-C works fine for me. > [@peter.ludemann](#): > > And when closing the trace window, “Exit from Prolog” simply returns to the [SWI-Prolog](https://www.swi-prolog.org/pldoc/doc_for?object=manual) REPL. That reproduces. Should be fixed. ---
**Author:** ![joseph-vidal-rosset](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/joseph-vidal-rosset/32/2594_2.png) [@joseph-vidal-rosset](https://swi-prolog.discourse.group/u/joseph-vidal-rosset)\ **Post date:** [July 28, 2025, 1:37pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/14 "2025-07-28T13:37:32Z")
On Debian 12: ```prolog root@mx:/usr/local/swipl-devel/build# ninja[1/923] Building C object packages/xpce/CMakeFiles/plugin_pl2xpce.dir/src/win/display.c.oFAILED: packages/xpce/CMakeFiles/plugin_pl2xpce.dir/src/win/display.c.o/usr/bin/cc -Dplugin_pl2xpce_EXPORTS -I/usr/local/swipl-devel/build/packages/xpce -I/usr/local/swipl-devel/packages/xpce/src -I/usr/include/freetype2 -I/usr/local/swipl-devel/src/os -I/usr/local/swipl-devel/src -O2 -gdwarf-2 -g3 -fPIC -fvisibility=hidden -Wall -DHAVE_CONFIG_H -DSWI -D __SWI_PROLOG__ -std=gnu11 -MD -MT packages/xpce/CMakeFiles/plugin_pl2xpce.dir/src/win/display.c.o -MF packages/xpce/CMakeFiles/plugin_pl2xpce.dir/src/win/display.c.o.d -o packages/xpce/CMakeFiles/plugin_pl2xpce.dir/src/win/display.c.o -c /usr/local/swipl-devel/packages/xpce/src/win/display.c/usr/local/swipl-devel/packages/xpce/src/win/display.c: In function ‘getDPIDisplay’:/usr/local/swipl-devel/packages/xpce/src/win/display.c:394:43: error: ‘NAME_dpi’ undeclared (first use in this function); did you mean ‘NAME_pie’?394 | Any rc = getClassVariableValueObject(d, NAME_dpi);| ^~~~~~~~| NAME_pie/usr/local/swipl-devel/packages/xpce/src/win/display.c:394:43: note: each undeclared identifier is reported only once for each function it appears inIn file included from /usr/local/swipl-devel/packages/xpce/src/win/display.c:36:/usr/local/swipl-devel/packages/xpce/src/win/display.c: At top level:/usr/local/swipl-devel/packages/xpce/src/win/display.c:1254:6: error: ‘NAME_dpi’ undeclared here (not in a function); did you mean ‘NAME_pie’?1254 | IV(NAME_dpi, “[size|int]”, IV_NONE,| ^~~~~~~~/usr/local/swipl-devel/packages/xpce/src/h/kernel.h:895:35: note: in definition of macro ‘IV’895 | #define IV(n, t, f, g, s) { n, t, f, NULL, (Name) g, s }| ^/usr/local/swipl-devel/packages/xpce/src/win/display.c:1272:6: error: ‘NAME_wmClass’ undeclared here (not in a function); did you mean ‘NAME_noClass’?1272 | IV(NAME_wmClass, “[name]”, IV_BOTH,| ^ ~~~~~~~~~~~ /usr/local/swipl-devel/packages/xpce/src/h/kernel.h:895:35: note: in definition of macro ‘IV’895 | #define IV(n, t, f, g, s) { n, t, f, NULL, (Name) g, s }| ^[6/923] Building C object packages/xpce/CMakeFiles/plugin_pl2xpce.dir/src/img/gifwrite.c.oninja: build stopped: subcommand failed.root@mx:/usr/local/swipl-devel/build# ``` ---
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [July 28, 2025, 1:44pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/15 "2025-07-28T13:44:01Z")
You should be fine with a clean build. Incremental builds normally work, but the old system had no mechanism to deal with changes to xpce’s “name” database. The most recent changes also lead to a upgrade issue wrt. building the .qlf files. That too should be fine using a clean build. If there is something useful in the build directory, run ```prolog ../scripts/clean-build ``` Of not, `rm -r` does the job. ---
**Author:** ![joseph-vidal-rosset](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/joseph-vidal-rosset/32/2594_2.png) [@joseph-vidal-rosset](https://swi-prolog.discourse.group/u/joseph-vidal-rosset)\ **Post date:** [July 28, 2025, 2:03pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/16 "2025-07-28T14:03:29Z")
```prolog Thanks Jan. As usual, your advice is very useful: 100% tests passed, 0 tests failed out of 82 ``` ```prolog Total Test time (real) = 19.85 secroot@mx:/usr/local/swipl-devel/build# ninja install[33/34] Install the project…– Install configuration: “PGO”– Set runtime path of “/root/lib/swipl/bin/x86_64-linux/swipl” to “/root/lib/swipl/lib/x86_64-linux”– Set runtime path of “/root/lib/swipl/lib/x86_64-linux/libswipl.so.9.3.26” to “/root/lib/swipl/lib/x86_64-linux”– Set runtime path of “/root/lib/swipl/bin/x86_64-linux/swipl-win” to “/root/lib/swipl/lib/x86_64-linux”– Set runtime path of “/root/lib/swipl/bin/x86_64-linux/swipl-ld” to “/root/lib/swipl/lib/x86_64-linux”root@mx:/usr/local/swipl-devel/build# exitexitjoseph@mx:/usr/local/swipl-devel$ cd ~/joseph@mx:~$ swipl --versionSWI-Prolog version 9.3.26 for x86_64-linux ``` ---
**Author:** ![alanbur](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/alanbur/32/7166_2.png) [@alanbur](https://swi-prolog.discourse.group/u/alanbur)\ **Post date:** [August 1, 2025, 9:37pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/17 "2025-08-01T21:37:56Z")
> [@jan](#): > > All now compiles completely clean on Debian Bookworm for me (started from a clean Docker image). It doesn’t for me, Debian 12.11, commit ee7aa973f7ff44f95751582b5ed343cba536cd16. I followed the instructions at [Prerequisites for Debian based systems (Ubuntu, Mint, ...)](https://www.swi-prolog.org/build/Debian.html) and [Building XPCE for SDL3 and Cairo · SWI-Prolog/packages-xpce Wiki · GitHub](https://github.com/SWI-Prolog/packages-xpce/wiki/Building-XPCE-for-SDL3-and-Cairo#porting-to-linux-distros-without-sdl3) and I get the following. My guess is a library path issue, but I haven’t had time to track it down any further. ```prolog OR: ''/1: Unknown procedure: pce:object/1 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:send/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/boot/pce_global.pl:115: Initialization goal raised exception: ERROR: pce_global:register_handler/0: Unknown procedure: pce_principal:send/2 ERROR: However, there are definitions for: ERROR: pce_principal:send/3 ERROR: pce_principal:send/4 ERROR: pce_principal:send/5 ERROR: pce_principal:send/6 ERROR: pce_principal:send/7 ERROR: pce_principal:send/8 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:send/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/boot/pce_autoload.pl:104: Initialization goal raised exception: ERROR: pce_autoload:register_handler/0: Unknown procedure: pce_principal:send/2 ERROR: However, there are definitions for: ERROR: pce_principal:send/3 ERROR: pce_principal:send/4 ERROR: pce_principal:send/5 ERROR: pce_principal:send/6 ERROR: pce_principal:send/7 ERROR: pce_principal:send/8 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:get/3 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/boot/pce_editor.pl:137: Initialization goal raised exception: ERROR: pce_principal:get/4: Unknown procedure: pce_principal:get/3 ERROR: However, there are definitions for: ERROR: pce_principal:get/4 ERROR: pce_principal:get/5 ERROR: pce_principal:get/6 ERROR: pce_principal:get/7 ERROR: pce_principal:get/8 ERROR: det/1 ERROR: get/1 ERROR: get0/1 ERROR: get/2 ERROR: get0/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:get/3 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/boot/pce_keybinding.pl:364: Initialization goal raised exception: ERROR: pce_principal:get/4: Unknown procedure: pce_principal:get/3 ERROR: However, there are definitions for: ERROR: pce_principal:get/4 ERROR: pce_principal:get/5 ERROR: pce_principal:get/6 ERROR: pce_principal:get/7 ERROR: pce_principal:get/8 ERROR: det/1 ERROR: get/1 ERROR: get0/1 ERROR: get/2 ERROR: get0/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:get/3 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/boot/pce_keybinding.pl:396: Initialization goal raised exception: ERROR: pce_principal:get/4: Unknown procedure: pce_principal:get/3 ERROR: However, there are definitions for: ERROR: pce_principal:get/4 ERROR: pce_principal:get/5 ERROR: pce_principal:get/6 ERROR: pce_principal:get/7 ERROR: pce_principal:get/8 ERROR: det/1 ERROR: get/1 ERROR: get0/1 ERROR: get/2 ERROR: get0/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:get/3 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/boot/pce_keybinding.pl:409: Initialization goal raised exception: ERROR: pce_keybinding:make_key_binding_style_type/0: Unknown procedure: pce_principal:get/3 ERROR: However, there are definitions for: ERROR: pce_principal:get/4 ERROR: pce_principal:get/5 ERROR: pce_principal:get/6 ERROR: pce_principal:get/7 ERROR: pce_principal:get/8 ERROR: det/1 ERROR: get/1 ERROR: get0/1 ERROR: get/2 ERROR: get0/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: [Thread 1]: exception handler failed to define pce_principal:send/2 ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:45: ERROR: /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/pce.pl:256: Initialization goal raised exception: ERROR: pce:set_version/0: Unknown procedure: pce_principal:send/2 ERROR: However, there are definitions for: ERROR: pce_principal:send/3 ERROR: pce_principal:send/4 ERROR: pce_principal:send/5 ERROR: pce_principal:send/6 ERROR: pce_principal:send/7 ERROR: pce_principal:send/8 ERROR: Unknown procedure: pce_principal:in_pce_thread_sync2/2 ERROR: In: ERROR: [15] pce_principal:in_pce_thread_sync2((gui_tracer: ...)-[],[]) ERROR: [14] pce:in_pce_thread_sync(gui_tracer:load_files(...,...)) at /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/pce.pl:157 ERROR: [13] gui_tracer:guitracer at /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:80 ERROR: [12] gui_tracer:gspy(user:true) at /opt/swipl-9.3.26+/lib/swipl/xpce/prolog/lib/gui_tracer.pl:159 ERROR: [11] toplevel_call(user:user: ...) at /opt/swipl-9.3.26+/lib/swipl/boot/toplevel.pl:1540 Exception: (15) pce_principal:in_pce_thread_sync2((gui_tracer:load_files([library('trace/trace')], [silent(true), if(not_loaded)]))-[], []) ? ``` ---
**Author:** ![alanbur](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/alanbur/32/7166_2.png) [@alanbur](https://swi-prolog.discourse.group/u/alanbur)\ **Post date:** [August 1, 2025, 9:59pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/18 "2025-08-01T21:59:10Z")
Yeah: ```prolog $ LD_LIBRARY_PATH=/usr/local/lib /opt/swipl-9.3.26+/bin/swipl ?- gspy(true). true. [debug] ?- ^D $ LD_DEBUG=files /opt/swipl-9.3.26+/bin/swipl ... ?- gspy(true). 1784603: 1784603: file=/opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so [0]; dynamically loaded by /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/libswipl.so.9 [0] 1784603: file=/opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so [0]; generating link map 1784603: dynamic: 0x00007f71f5a3ed20 base: 0x00007f71f5800000 size: 0x0000000000299e18 1784603: entry: 0x00007f71f5800000 phdr: 0x00007f71f5800040 phnum: 9 1784603: 1784603: 1784603: file=libSDL3_image.so.0 [0]; needed by /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so [0] ... $ ldd /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so | grep 'not found' libSDL3_image.so.0 => not found libSDL3.so.0 => not found $ readelf -d /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so Dynamic section at offset 0x23dd20 contains 31 entries: Tag Type Name/Value 0x0000000000000001 (NEEDED) Shared library: [libSDL3_image.so.0] 0x0000000000000001 (NEEDED) Shared library: [libSDL3.so.0] ... # patchelf --add-rpath /usr/local/lib /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so $ readelf -d /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so Dynamic section at offset 0x10ba000 contains 32 entries: Tag Type Name/Value 0x000000000000001d (RUNPATH) Library runpath: [/usr/local/lib] 0x0000000000000001 (NEEDED) Shared library: [libSDL3_image.so.0] 0x0000000000000001 (NEEDED) Shared library: [libSDL3.so.0] $ ldd /opt/swipl-9.3.26+/lib/swipl/lib/x86_64-linux/pl2xpce.so linux-vdso.so.1 (0x00007fffa378c000) libSDL3_image.so.0 => /usr/local/lib/libSDL3_image.so.0 (0x00007f7098ff4000) libSDL3.so.0 => /usr/local/lib/libSDL3.so.0 (0x00007f7098800000) ... $ /opt/swipl-9.3.26+/bin/swipl ?- gspy(true). true. [debug] ?- ``` That’s a dirty hack - it needs fixing properly in whatever configures/builds pl2xpce.so. ---
**Author:** ![alanbur](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/alanbur/32/7166_2.png) [@alanbur](https://swi-prolog.discourse.group/u/alanbur)\ **Post date:** [August 1, 2025, 10:22pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/19 "2025-08-01T22:22:50Z")
It’s “working” but only for a loose definition of working. Font size is huge and on a dual monitor setup if I run the debugger on the RHS screen and open a child window, its placement is almost entirely off the RHS side the screen. If I do the same on the LHS screen, the child window is split between the two monitors. ---
**Author:** ![peter.ludemann](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/peter.ludemann/32/48_2.png) [@peter.ludemann](https://swi-prolog.discourse.group/u/peter.ludemann)\ **Post date:** [August 1, 2025, 10:44pm UTC](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120/20 "2025-08-01T22:44:39Z")
> [@alanbur](#): > > Font size is huge You might try setting `font.scale: 1.0` in the `Defaults` file (see my discussion with Jan on July 24 for other parameters) [Next page](https://swi-prolog.discourse.group/t/ann-swi-prolog-9-3-26/9120.md?page=2)