martes, 15 de agosto de 2017

Qt 4 removal in Debian testing (Buster)/unstable

We have been announcing it: we are going to remove Qt 4 during the Buster cycle.

Or at least that's the best outcome we can expect. Removing a very highly used library is hard, as Qt4's Webkit has proved. Qt 4 is long dead upstream and we have already started to need to patch it with untested patches as in the OpenSSL 1.1 case (will be in experimental in a few hours after this post).

We will try to put as less effort as possible in keeping it alive meaning that from now on if we need to patch it to make it support a newer lib or alike we will simply remove its support if possible. Using the OpenSSL case as an example, if we need to support any version > 1.1 we will simply remove the SSL support. That means things will break.

So, if you depend on FLOSS which is still based on Qt 4 be sure to try to port it. If you depend on a proprietary vendor software which uses Qt 4 then you better start telling them it's really time to update it. Really.

We will soon start filing bugs against packages using Qt 4. I'll update this blog post later to add that info.

For the Qt/KDE team, Lisandro.

sábado, 24 de junio de 2017

Qt 5.7 submodules that didn't make it to Stretch but will be in testing

There are two Qt 5.7 submodules that we could not package in time for Strech but are/will be available in their 5.7 versions in testing. This are qtdeclarative-render2d-plugin and qtvirtualkeyboard.

declarative-render2d-plugin makes use of the Raster paint engine instead of OpenGL to render the  contents of a scene graph, thus making it useful when Qt Quick2 applications  are run in a system without OpenGL 2  enabled hardware. Using it might require tweaking Debian's /etc/X11/Xsession.d/90qt5-opengl. On Qt 5.9 and newer this plugin is merged in Qt GUI so there should be no need to perform any action on the user's behalf.

Debian's VirtualKeyboard currently has a gotcha: we are not building it with the embedded code it ships. Upstream ships 3rd party code but lacks a way to detect and use the system versions of them. See QTBUG-59594, patches are welcomed. Please note that we prefer patches sent directly upstream to the current dev revision, we will be happy to backport patches if necessary.
Yes, this means no hunspell, openwnn, pinyin, tcime nor lipi-toolkit/t9write support.

Note 2017-07-16: please use 5.7.1+dfsg-2, it fixes a wrong dependency and adds use of the system's hunspell.

miércoles, 22 de febrero de 2017

Developing an nrf51822 based embedded device with Qt Creator and Debian

I'm currently developing an nRF51822-based embedded device. Being one the Qt/Qt Creator maintainers in Debian I would of course try to use it for the development. Turns out it works pretty good... with some caveats.

There are already two quite interesting blog posts about using Qt Creator on MAC and on Windows, so I will not repeat the basics, as they are there. Both use qbs, but I managed to use CMake.

Instead I'll add some tips on the stuff that I needed to solve in order to make this happen on current Debian Sid.


  • The required toolchain is already in Debian, just install binutils-arm-none-eabi, gcc-arm-none-eabi and gdb-arm-none-eabi.
  • You will not find arm-none-eabi-gdb-py on the gdb-arm-none-eabi package. Fear not, the provided gdb binary is compiled against python so it will work.
  • To enable proper debugging be sure to follow this flag setup. If you are using CMake like in this example be sure to modify CMake/toolchain_gcc.cmake as necessary.
  • In Qt Creator you might find that, while try to run or debug your app, you are greated with a message box that says "Cannot debug: Local executable is not set." Just go to Projects →Run and change "Run configuration" until you get a valid path (ie, a path to the .elf or .out file) in the "Executable" field.

Cheers!