# Gtk-fortran 20.04 released, preparing for GTK 4 **URL:** \ **Category:** Announcements\ **Created:** [May 15, 2020, 7:59pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45 "2020-05-15T19:59:03Z")\ **Posts on this page:** 12\ **Page:** 2
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 24, 2020, 8:18am UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/21 "2020-07-24T08:18:41Z")
Daunting is the word! GTK is a huge API, a world in itself. I plan in the next months to add more tutorials. Up to now, the program examples were the only way to learn gtk-fortran. But I was inspired by this post: [https://github.com/fortran-lang/stdlib/issues/182](https://github.com/fortran-lang/stdlib/issues/182) about documentation. Regrettably, it is true there is very few books about GTK. In the Tutorials page, you will find those two books: - Andrew Krause, [Foundations of GTK+ Development](http://www.apress.com/9781590597934), _Apress_ , 2007, ISBN-13: 978-1-59059-793-4, 630pp. - David Ashley, Andrew Krause, [Foundations of PyGTK Development - GUI Creation with Python](https://www.apress.com/gp/book/9781484241783), _Apress_ , 2019, ISBN-13: 978-1-4842-4178-3, 563pp. The first one is excellent, C oriented, but now obsolete (GTK 2). The second one is the GTK 3 version but for Python. Unhappily, I think it is easier to adapt C GTK code to Fortran than Python GTK code (higher level than the original). For GTK 3, I recommend: [https://www.youtube.com/c/MichaelB-GTK/videos](https://www.youtube.com/c/MichaelB-GTK/videos) Michael B. has posted on its channel more than 200 videos on GTK 3 programming (C language)! Having personally only tested gtk-fortran on Windows 7, have you encountered specific problems (not stated in the documentation) with Windows 10? ---
**Author:** ![Pompito](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@Pompito](https://fortran-lang.discourse.group/u/Pompito)\ **Post date:** [July 24, 2020, 6:33pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/22 "2020-07-24T18:33:58Z")
The only issue I found, but solved easily, was when doing `make` after cmake. Make tried to compile a fortran source file with a line longer than 132 characters and GFortran (10.1) issued an error, not warning, thus stopping the build. I just searched the culprit line and split it with an ampersand and voila. I should mention that I did ` wget https://github.com/vmagnin/gtk-fortran/archive/gtk3.tar.gz` instead of pulling with git. I could check which file was later. The examples I tried (julia, mandelbrot, and some more) were working fine. ---
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 24, 2020, 6:57pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/23 "2020-07-24T18:57:33Z")
> I could check which file was later. I am interested to know the culprit. I have never encountered that error. > The examples I tried (julia, mandelbrot, and some more) were working fine. 😀 ---
**Author:** ![Pompito](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@Pompito](https://fortran-lang.discourse.group/u/Pompito)\ **Post date:** [July 24, 2020, 8:53pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/24 "2020-07-24T20:53:15Z")
Here is the error: ```auto [89%] Building Fortran object sketcher/CMakeFiles/gtkf-sketcher.dir/gtkf-sketcher.out.f90.obj f951.exe: Warning: Nonexistent include directory 'C:/Dev/msys64/mingw64/lib/libffi-3.2.1/include' [-Wmissing-include-dirs] C:/Users/Francisco/Desktop/test/gtk-fortran-gtk3/build/sketcher/gtkf-sketcher.out.f90:596:132: 596 | call execute_command_line("python3 C:/Program Files (x86)/gtk-fortran/bin/gtk-3-fortran-pymodscan .", exitstat=shellout_err) | 1 Error: Line truncated at (1) [-Werror=line-truncation] C:/Users/Francisco/Desktop/test/gtk-fortran-gtk3/build/sketcher/gtkf-sketcher.out.f90:596:132: 596 | call execute_command_line("python3 C:/Program Files (x86)/gtk-fortran/bin/gtk-3-fortran-pymodscan .", exitstat=shellout_err) | 1 Error: Syntax error in argument list at (1) C:/Users/Francisco/Desktop/test/gtk-fortran-gtk3/build/sketcher/gtkf-sketcher.out.f90:878:7: 878 | use handlers | 1 Fatal Error: Cannot open module file 'handlers.mod' for reading at (1): No such file or directory f951.exe: some warnings being treated as errors compilation terminated. make[2]: *** [sketcher/CMakeFiles/gtkf-sketcher.dir/build.make:83: sketcher/CMakeFiles/gtkf-sketcher.dir/gtkf-sketcher.out.f90.obj] Error 1 make[1]: *** [CMakeFiles/Makefile2:1518: sketcher/CMakeFiles/gtkf-sketcher.dir/all] Error 2 make: *** [Makefile:183: all] Error 2 ``` After splitting the culprit line in /build/sketcher/gtkf-sketcher.out.f90 and doing `make` again it works fine. ---
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 24, 2020, 9:03pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/25 "2020-07-24T21:03:30Z")
Thanks very much! That code was added this week. And the path to `gtk-3-fortran-pymodscan` is added by CMake. It is probably a little bit longer in Windows if you install in C:\Program Files (x86). I will work on that tomorrow. Note also that I have recently added on the wiki: > - Install the gtk-?-fortran library into your MSYS2 directory (by default CMake uses C:\Program Files (x86) but the spaces will cause problems with pkg-config): > > `$ MSYS2_ARG_CONV_EXCL=- cmake . -G"MSYS Makefiles" -DCMAKE_INSTALL_PREFIX=$MINGW_PREFIX $ make -j install DESTDIR=/` > > That solution was found at [cmake msys2, wrong install path for library - Stack Overflow](https://stackoverflow.com/questions/44282788/cmake-msys2-wrong-install-path-for-library) ---
**Author:** ![stavros](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@stavros](https://fortran-lang.discourse.group/u/stavros)\ **Post date:** [July 25, 2020, 8:09am UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/26 "2020-07-25T08:09:46Z")
Hi @vmagnin, I just started with gtk-3-fortran. I followed the installation instructions, and everything was installed successfully and a couple of examples that I tested also run ok. Just completed your first tutorial as well. Thank you for all the work you are doing there! I only want to note a small detail and please correct me if I am wrong: gtk-3-fortran lib seems to be compiled with GNU Fortran v7.5.0? When tried your first tutorial I had to go backwards from 10 to 9, 8, and finally got it working with 7, by replacing in the command line `gfortran` with `gfortran-7` (at least for my case that I have several versions installed). example error: ```bash ~/Projects/GTK_Apps/tutorials/tutorial_1$ gfortran my_first_gtk_app.f90 $(pkg-config --cflags --libs gtk-3-fortran) my_first_gtk_app.f90:3:9: 3 | use gtk, only: gtk_application_new, G_APPLICATION_FLAGS_NONE, & | 1 Fatal Error: Cannot read module file ‘/usr/local/include/gtk-3-fortran/gtk.mod’ opened at (1), because it was created by a different version of GNU Fortran compilation terminated. ``` Nothing important, but if that is the case perhaps you could mention this at the beginning of the tutorials for new users like myself. ---
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 25, 2020, 8:45am UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/27 "2020-07-25T08:45:57Z")
Thanks @stavros for feedback! Normally, it is CMake which detects the Fortran compiler of the system: ``` $ cmake .. -- The Fortran compiler identification is GNU 9.2.1 -- Check for working Fortran compiler: /usr/bin/f95 ... ``` On my Ubuntu system, I have gfortran 4.8, 5.5, 7.5, 8.5, 9.2. But the command `gfortran` corresponds to: ``` $ gfortran --version GNU Fortran (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008 ``` What are the versions printed by those two commands on your system? (and what is your system? It is an interesting problem that I have never encountered). Note that you can choose which compiler who want to use with that command: `$ cmake -D CMAKE_Fortran_COMPILER:FILEPATH=`which gfortran-9` ..` ---
**Author:** ![stavros](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@stavros](https://fortran-lang.discourse.group/u/stavros)\ **Post date:** [July 25, 2020, 9:18am UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/28 "2020-07-25T09:18:36Z")
You are correct and I would expect the same thing… I have installed in my system all versions from 7.5 up to 10.1 with default the latest. I am using Mint 19.1, which is based on Ubuntu 18.04. ```bash $ gfortran --version GNU Fortran (Ubuntu 10.1.0-2ubuntu1~18.04) 10.1.0 ``` I control the different versions through `update-alternatives`: ```bash $ update-alternatives --config gfortran There are 4 choices for the alternative gfortran (providing /usr/bin/gfortran). Selection Path Priority Status ------------------------------------------------------------ * 0 /usr/bin/gfortran-10 40 auto mode 1 /usr/bin/gfortran-10 40 manual mode 2 /usr/bin/gfortran-7 10 manual mode 3 /usr/bin/gfortran-8 20 manual mode 4 /usr/bin/gfortran-9 30 manual mode ``` however the cmake recognises 7.5 when I run it from within the project: ```bash gtk-fortran/build$ cmake .. -- Building gtk-3-fortran -- GNUInstallDirs: /usr/local lib include bin share share/man -- System: Linux 4.15.0-96-generic x86_64 -- Compiler: GNU 7.5.0 /usr/bin/f95 -- Build type is: release -- Compilation flags: -pthread -O3 -mtune=native -march=native -- Configuring done -- Generating done -- Build files have been written to:... ``` Any idea why? ---
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 25, 2020, 9:31am UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/29 "2020-07-25T09:31:13Z")
> [@stavros](#): > > Any idea why? No, I never had that problem. But I do not use `update-alternatives` (thanks, I didn’t know that command). It seems CMake have chosen the version with the lowest priority! ---
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 25, 2020, 10:28am UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/30 "2020-07-25T10:28:28Z")
In my notes, I had noted that CMake uses `f95`, which is a link toward the default Fortran compiler: ``` $ f95 --version GNU Fortran (Ubuntu 9.3.0-10ubuntu2) 9.3.0 ``` ---
**Author:** ![stavros](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@stavros](https://fortran-lang.discourse.group/u/stavros)\ **Post date:** [July 25, 2020, 6:27pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/31 "2020-07-25T18:27:57Z")
Didn’t know about f95 but I just checked and there is no difference: ```bash $ f95 --version GNU Fortran (Ubuntu 10.1.0-2ubuntu1~18.04) 10.1.0 ``` ---
**Author:** ![vmagnin](https://yyz2.discourse-cdn.com/free1/user_avatar/fortran-lang.discourse.group/vmagnin/32/28_2.png) [@vmagnin](https://fortran-lang.discourse.group/u/vmagnin)\ **Post date:** [July 25, 2020, 7:13pm UTC](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45/32 "2020-07-25T19:13:47Z")
> [@stavros](#): > > `update-alternatives` Strange… Perhaps you could see on [https://discourse.cmake.org/](https://discourse.cmake.org/) [Previous page](https://fortran-lang.discourse.group/t/gtk-fortran-20-04-released-preparing-for-gtk-4/45.md?page=1)