Search Results: "lisandro"

12 November 2023

Lisandro Dami n Nicanor P rez Meyer: Mini DebConf 2023 in Montevideo, Uruguay

15 years, "la ni a bonita", if you ask many of my fellow argentinians, is the amount of time I haven't been present in any Debian-related face to face activity. It was already time to fix that. Thanks to Santiago Ruano Rinc n and Gunnar Wolf that proded me to come I finally attended the Mini DebConf Uruguay in Montevideo. Me in Montevideo, Uruguay I took the opportunity to do my first trip by ferry, which is currently one of the best options to get from Buenos Aires to Montevideo, in my case through Colonia. Living ~700km at the south west of Buenos Aires city the trip was long, it included a 10 hours bus, a ferry and yet another bus... but of course, it was worth it. In Buenos Aires' port I met Emmanuel eamanu Arias, a fellow Argentinian Debian Developer from La Rioja, so I had the pleasure to travel with him. To be honest Gunnar already did a wonderful blog post with many pictures, I should have taken more. I had the opportunity to talk about device trees, and even look at Gunnar's machine one in order to find why a Display Port port was not working on a kernel but did in another. At the same time I also had time to start packaging qt6-grpc. Sadly I was there just one entire day, as I arrived on Thursday afternoon and had to leave on Saturday after lunch, but we did have a lot of quality Debian time. I'll repeat here what Gunnar already wrote:
We had a long, important conversation about an important discussion that we are about to present on
Stay tuned on that, I think this is something we should all get involved. All in all I already miss hacking with people on the same room. Meetings for us mean a lot of distance to be traveled (well, I live far away of almost everything), but I really should try to this more often. Certainly more than just once every 15 years :-)

11 November 2023

Gunnar Wolf: There once was a miniDebConf in Uruguay...

Meeting Debian people for having a good time together, for some good hacking, for learning, for teaching Is always fun and welcome. It brings energy, life and joy. And this year, due to the six-months-long relocation my family and me decided to have to Argentina, I was unable to attend the real deal, DebConf23 at India. And while I know DebConf is an experience like no other, this year I took part in two miniDebConfs. One I have already shared in this same blog: I was in MiniDebConf Tamil Nadu in India, followed by some days of pre-DebConf preparation and scouting in Kochi proper, where I got to interact with the absolutely great and loving team that prepared DebConf. The other one is still ongoing (but close to finishing). Some months ago, I talked with Santiago Ruano, jokin as we were Spanish-speaking DDs announcing to the debian-private mailing list we d be relocating to around R o de la Plata. And things worked out normally: He has been for several months in Uruguay already, so he decided to rent a house for some days, and invite Debian people to do what we do best. I left Paran Tuesday night (and missed my online class at UNAM! Well, you cannot have everything, right?). I arrived early on Wednesday, and around noon came to the house of the keysigning (well, the place is properly called Casa Key , it s a publicity agency that is also rented as a guesthouse in a very nice area of Montevideo, close to Nuevo Pocitos beach). In case you don t know it, Montevideo is on the Northern (or Eastern) shore of R o de la Plata, the widest river in the world (up to 300Km wide, with current and non-salty water). But most important for some Debian contributors: You can even come here by boat! That first evening, we received Ilu, who was in Uruguay by chance for other issues (and we were very happy about it!) and a young and enthusiastic Uruguayan, Felipe, interested in getting involved in Debian. We spent the evening talking about life, the universe and everything Which was a bit tiring, as I had to interface between Spanish and English, talking with two friends that didn t share a common language On Thursday morning, I went out for an early walk at the beach. And lets say, if only just for the narrative, that I found a lost penguin emerging from R o de la Plata! For those that don t know (who d be most of you, as he has not been seen at Debian events for 15 years), that s Lisandro Dami n Nicanor P rez Meyer (or just lisandro), long-time maintainer of the Qt ecosystem, and one of our embedded world extraordinaires. So, after we got him dry and fed him fresh river fishes, he gave us a great impromptu talk about understanding and finding our way around the Device Tree Source files for development boards and similar machines, mostly in the ARM world. From Argentina, we also had Emanuel (eamanu) crossing all the way from La Rioja. I spent most of our first workday getting my laptop in shape to be useful as the driver for my online class on Thursday (which is no small feat people that know the particularities of my much loved ARM-based laptop will understand), and running a set of tests again on my Raspberry Pi labortory, which I had not updated in several months. I am happy to say we are also finally also building Raspberry images for Trixie (Debian 13, Testing)! Sadly, I managed to burn my USB-to-serial-console (UART) adaptor, and could neither test those, nor the oldstable ones we are still building (and will probably soon be dropped, if not for anything else, to save disk space). We enjoyed a lot of socialization time. An important highlight of the conference for me was that we reconnected with a long-lost DD, Eduardo Tr pani, and got him interested in getting involved in the project again! This second day, another local Uruguayan, Mauricio, joined us together with his girlfriend, Alicia, and Felipe came again to hang out with us. Sadly, we didn t get photographic evidence of them (nor the permission to post it). The nice house Santiago got for us was very well equipped for a miniDebConf. There were a couple of rounds of pool played by those that enjoyed it (I was very happy just to stand around, take some photos and enjoy the atmosphere and the conversation). Today (Saturday) is the last full-house day of miniDebConf; tomorrow we will be leaving the house by noon. It was also a very productive day! We had a long, important conversation about an important discussion that we are about to present on It has been a great couple of days! Sadly, it s coming to an end But this at least gives me the opportunity (and moral obligation!) to write a long blog post. And to thank Santiago for organizing this, and Debian, for sponsoring our trip, stay, foods and healthy enjoyment!

28 September 2023

Lisandro Dami n Nicanor P rez Meyer: sd-mux-ctrl in Debian

Part of what I love to do is to play with embedded devices running Linux. And many times I need to juggle with an SD card in order to copy a filesystem to a board... until I found SDWire. SDWire v1.4, top view SDWire v1.4, bottom view This little gadget is an SD muxer: it allows you to use it as a "normal" card reader or switch the SD card to the SD card slot. So next time I need to copy contents to a SD card and then push it to a board I can just do it from the command line. Now the software to control this device was not in Debian, so I fixed that. I am keeping the code and the packaging on GitLab, as "The Tizen project is not anymore really active". At the time of writing the package was just accepted, so it might take a couple of hours to be available on the archive. Enjoy!

8 July 2023

Lisandro Dami n Nicanor P rez Meyer: Open question: Podman and user/group IDs

Here is an open question for Podman users: is there a (ideally simple) way to keep the user/group ID between the real system and the container? Let me be more verbose. I use Docker mostly in two "special" cases: Now in both setups I mount some system directory into the chroot, normally as $HOME. Using Docker I can do the right UID/GID mapping and any file I create inside the container will have my system's UID/GID. And that's the thing I so far could not do with Podman. So dear Podman user: is there any way to do this with Podman? If you know, please feel free to send a comment/email!

16 June 2023

Lisandro Dami n Nicanor P rez Meyer: Qt 6 in Debian bullseye, take 2

Bookworm has been released and Bullseye is now old-stable. Non the less today I took the time to update the Qt 6 backports so they are as close as Bookworm as possible. Except security fixes are needed these ought to be the latest uploads of Qt 6 to bullseye-backports. Hope you enjoyed them, and thanks again The Qt Company and ICS for making this possible.

8 June 2023

Lisandro Dami n Nicanor P rez Meyer: Adventures in Debian's Qt land

Debian (I might as well say "we", this is the beauty of it) is about to release Debian 12 aka Bookworm. Let's take a quick look at what is new in Debian Qt land. Qt 5 Bookworm has Qt 5.15.8, which is nothing but great news. KDE will be switching to Qt 6 sooner than later and Qt 5 has been a fun ride, but Dmitry Shachnev and I needed a break, or at very least not handling two Qt versions. But in the end I need to be fair: you REALLY need to thank Dmitry for Qt 5. He has been the man power behind it in 99.5% of the cases. Qt 6 This will be the first Debian release to have official Qt 6 packages. NOTHING would have happened if it weren't for Patrick "Delta-One" Franz standing up to maintain it. BIG kudos to him! Well, there is a "little lie" in the paragraph above. Thanks to The Qt Company and ICS the current Qt 6 version, 6.4.2, is also available as Bullseye's backports. The Qt Company really also helped us here by providing us almost-to-be-released tarballs of Qt 6.4.2 so we were able to push them to unstable and do a transition in time for freeze, thanks a lot for that! So, what is the Qt 6 state? At the binary side all but OpenGL ES support should be there. Sadly this was discovered too late in the release process and we still might need help maintaining it (read the link to know why!). We are still not building the documentation. Properly building the whole documentation, as with Qt 5, would require all the Qt submodules' source code in one place, which we can't (easily?) do in Debian. So building the doc means hacking the build system and getting semi-linked documentation, much like with Qt 5. Now if you think you have an idea to solve this... we are happy to hear from you! Another great thing to know about Qt 6 is that, thanks to Helmut Grohne, pure Qt 6 applications should be able to cross compile. Applications using multi-arch enabled libraries ought to work too. Even more, many Qt submodules themselves should also cross compile! Not all of them, as we missed some patches in time, but hey, if you need to cross compile Qt, you surely can apply them yourselves! And finally tests, unit tests. In Qt 5 we had some of those, but none yet in Qt 6. This is one of the areas I would love to be able to put time... but time is scarce. The future? In my point of view the Debian 13 "Trixie" development cycle will see Qt 5 diminishing it's usage and Qt 6 becoming the major Qt version used, but from the Qt 4 experience I do not expect Qt 5 being dropped during this release cycle... let's see what the future brings us. Thanks! While I mentioned Dmitry and Patrick many more people helped us reach this place. I personally want to thank the people behind the KDE software, both upstream and, of course, the Debian maintainers. You should be thankful with them too, many hours of effort go into this. And thanks to you our dear users. We are normally overflowed with what we have in our hands and might not be up to the task sometimes, but hey, you are part of the reason we are doing this!

10 June 2022

Lisandro Dami n Nicanor P rez Meyer: Qt 6 in Debian bullseye

As announced some time ago on Debian Backport s mailing list I will be backporting Qt 6 to Debian 11 Bullseye . This comprises the (so far) 29 source packages that compose Qt 6 and libassimp. The Qt Company wanted to let us Debian users also enjoy Qt 6 on Bullseye, so they contacted me (and by extension my employer ICS) to bring this forward. As said in the mail I sent to the backports list I m making the commitment to maintain the packages myself, but I m really happy the Qt Company asked me for this. You can download Qt 6 for Debian Bullseye s backports by following the instructions. Also a big kudos to IOhannes m zm lnig, the assimp maintainer, who promptly helped me to get it backported. Enjoy!

21 October 2021

Lisandro Dami n Nicanor P rez Meyer: CMake toolchain files with Debian's cross compilers

Almost a year ago I added a script made by Helmut Grohne that is able to create a CMake toolchain file pre-filled with Debian-specifics ross compilers. The tool is installed by the cmake package and located at /usr/share/cmake/debtoolchainfilegen. It's usage is simple:
debtoolchainfilegen (arch) > cmake_toolchain_<arch>.cmake
Where $arch can be any of the Debian supported architectures, like arm64 (aka aarch64):
$ /usr/share/cmake/debtoolchainfilegen arm64 > /tmp/cmake_toolchain_aarch64
dpkg-architecture: warning: specified GNU system type aarch64-linux-gnu does not match CC system type x86_64-linux-gnu, try setting a correct CC environment variable
dpkg-architecture: warning: specified GNU system type aarch64-linux-gnu does not match CC system type x86_64-linux-gnu, try setting a correct CC environment variable
$ cat /tmp/cmake_toolchain_aarch64
# Use it while calling CMake:
#   mkdir build; cd build
#   cmake -DCMAKE_TOOLCHAIN_FILE="/path/to/cmake_toolchain_<arch>.cmake" ../
set(CMAKE_C_COMPILER "aarch64-linux-gnu-gcc")
set(CMAKE_CXX_COMPILER "aarch64-linux-gnu-g++")
set(PKG_CONFIG_EXECUTABLE "aarch64-linux-gnu-pkg-config")
set(PKGCONFIG_EXECUTABLE "aarch64-linux-gnu-pkg-config")
set(QMAKE_EXECUTABLE "aarch64-linux-gnu-qmake")
Note: I kept the warnings, which can be ignored and won't end up on the final file. As you might have noticed the file itself has instructions on how to use it. Of course we will need the requires cross toolchain for the selected arch. For example using arm64:
$ apt install crossbuild-essential-arm64
That's it, we can now start cross building our cmake-based software.

22 June 2021

Lisandro Dami n Nicanor P rez Meyer: Creating an app with QML: a heater control

Last week I took the ICS course "Building an Embedded Application with Qt" and now it's time to put the gained knowledge into action. I decided to create an application to (simulate?) a heater control. Why? Because I have a very basic one at home, and I always dreamed of getting something better. So time to implement it.
Requirements General Try to do the business logic in C++ as much as possible. Thermostat Temperature profiles Profile selection The system should be able to configure the desired profile in slots of 15' for each day (Monday to Sunday). So 96 slots per day. Manual button Sometimes I want to override the predefined configuration for a special situation. This button should allow me to set a new target temperature in a time slot from 15 minutes to 3 hours. Heater on indicator We want to know when the heater is being commanded to turn on. Temperature sensor This is not strictly decided, so the ability to use different kinds of sensors, one at a time, would be just nice.
User interface I did some sketches on what I would want as a UI. But I'm not a graphic designer, so I will first do a very simple but yet functional UI and then try to switch to a better designed UI. I dream on emulating an horizontal disc gauge, those where the user sees the border of the disc and the center of it shows the current temperature, perhaps even with a magnifier in the middle. Something like this, but with the needle fixed in the center.
Implementing the idea The backend Code repository at GitLab. My first steps where to implement the C++ backend: a Settings class and a TemperatureEngine class. For the temperature sensor I decided to make a very simple AbstractTemperatureSensor class and also implement a FakeTemperatureSensor. The later will come handy in order to be able to run tests. Later on I can implement other temperature sources like reading an analog voltage from some GPIO, getting the data trough MQTT, etc. The GUI That's definitely Work In Progress :-)

21 June 2021

Lisandro Dami n Nicanor P rez Meyer: Firsts steps into QML

After years of using and maintaining Qt there was a piece of the SDK that I never got to use as a developer: QML. Thanks to ICS I've took the free (in the sense of cost) QML Programming Fundamentals and Beyond. It consists of seven sessions, which can be easily done in a few days. I did them all in 4 days, but with enough time available you can do them even faster. Of course some previous knowledge of Qt comes handy. The only drawback was the need of a corporate e-mail in order to register (or at least the webpage says so). Apart from that it is really worth the effort. So, if you are planning into getting into QML this is definitely a nice way to start.

12 October 2020

Norbert Preining: KDE/Plasma Status Update 2020-10-12

Update 2020-10-19: All packages are now available in Debian/experimental! More than a month has passed since my last KDE/Plasma for Debian update, but things are progressing nicely. OBS packages On the OBS side, I have updated the KDE Apps to 20.08.2, and the KDE Frameworks to 5.75. Especially the update of apps brings in at least a critical security fix. Concerning the soon to be released Plasma 5.20, packages are more or less ready, but as reported here we have to wait for Qt 5.15 to be uploaded to unstable, which is also planned in the near future. Debian main packages Uploads of Plasma 5.19.4 to Debian/experimental are processing nicely, more than half the packages are already done, and the rest is ready to go. What holds us back is the NEW queue, as usual. We (Scarlett, Patrick, me) hope to have everything through NEW and in experimental as soon as possible, followed by an upload of probably Plasma 5.19.5 to Debian/unstable. Thanks also to Lisandro for accepting me into the Salsa Qt/KDE team.

18 August 2020

Lisandro Dami n Nicanor P rez Meyer: Stepping down as Qt 6 maintainers

After quite some time maintaining Qt in Debian both Dmitry Shachnev and I decided to not maintain Qt 6 when it's published (expected in December 2020, see We will do our best to keep the Qt 5 codebase up and running.

We **love** Qt, but it's a huge codebase and requires time and build power, both things that we are currently lacking, so we decided it's time for us to step down and pass the torch. And a new major version seems the right point to do that.

We will be happy to review and/or sponsor other people's work or even occasionally do uploads, but we can't promise to do it regularly.

Some things we think potential Qt 6 maintainers should be familiar with are, of course, C++ packaging (specially symbols files) and CMake, as Qt 6 will be built with it.

We also encourage prospective maintainers to remove the source's -everywhere-src suffixes and just keep the base names as source package names: qtbase6, qtdeclarative6, etc.

It has been an interesting ride all these years, we really hope you enjoyed using Qt.

Thanks for everything,

Dmitry and Lisandro.Note 20200818 12:12 ARST: I was asked if the move has anything to do with code quality or licensing. The answer is a huge no, Qt is a **great** project which we love. As stated before it's mostly about lack of free time to properly maintain it.

2 June 2020

Lisandro Dami n Nicanor P rez Meyer: Simplified Monitoring of Patients in Situations of Mass Hospitalization (MoSimPa) - Fighting COVID-19

I have been quite absent from Debian stuff lately, but this increased since COVID-19 hits us. In this blog post I'll try to sketch what I have been doing to help fight COVID-19 this last few months.

In the beginningWhen the pandemic reached Argentina the government started a quarantine. We engineers (like engineers around the world) started to think on how to put our abilities in order to help with the situation. Some worked toward providing more protection elements to medical staff, some towards increasing the number of ventilation machines at disposal. Another group of people started thinking on another ways of helping. In Bah a Blanca arised the idea of monitoring some variables remotely and in masse.

Simplified Monitoring of Patients in Situations of Mass Hospitalization (MoSimPa)

This is where the idea of remotely monitored devices came in, and MoSimPa (from the spanish of "monitoreo simplificado de pacientes en situaci n de internaci n masiva") started to get form. The idea is simple: oximetry (SpO2), heart rate and body temperature will be recorded and, instead of being shown in a display in the device itself, they will be transmitted and monitored in one or more places. In this way medical staff doesn't has to reach a patient constantly and monitoring could be done by medical staff for more patients at the same time. In place monitoring can also happen using a cellphone or tablet.

The devices do not have a screen of their own and almost no buttons, making them more cheap to build and thus more in line with the current economic reality of Argentina.

This is where the project Para Ayudar was created. The project aims to produce the aforementioned non-invasive device to be used in health institutions, hospitals, intra hospital transports and homes.

It is worth to note that the system is designed as a complementary measure for continuous monitoring of a pacient. Care should be taken to check that symptomps and overall patient status don't mean an inmediate life threat. In other words, it is NOT designed for ICUs.

All the above done with Free/Libre/Open Source software and hardware designs. Any manufacturing company can then use them for mass production.

The importance of early pneumonia detection

We were already working in MoSimPa when an NYTimes article caught or attention: "The Infection That s Silently Killing Coronavirus Patients". From the article:

A vast majority of Covid pneumonia patients I met had remarkably low oxygen saturations at triage seemingly incompatible with life but they were using their cellphones as we put them on monitors. Although breathing fast, they had relatively minimal apparent distress, despite dangerously low oxygen levels and terrible pneumonia on chest X-rays.

This greatly reinforced the idea we were on the right track.

The project from a technical standpoint

As the project is primarily designed for and by Argentinians the current system design and software documentation is written in spanish, but the source code (or at least most of it) is written in english. Should anyone need it in english please do not hesitate in asking me.

General system description

System schema

The system is comprised of the devices, a main machine acting as a server (in our case for small setups a Raspberry Pi) and the possibility of accessing data trough cell phones, tablets or other PCs in the network.

The hardware

As of today this is the only part in which I still can't provide schematics, but I'll update this blog post and technical doc with them as soon as I get my hands into them.

Again the design is due to be built in Argentina where getting our hands on hardware is not easy. Moreover it needs to be as cheap as possible, specially now that the Argentinian currency, the peso, is every day more depreciated. So we decided on using an ESP32 as the main microprocessor and a set of Maxim sensors devices. Again, more info when I have them at hand.

The software

Here we have many more components to describe. Firstly the ESP32 code is done with the Arduino SDK. This part of the stack will receive many updates soon, as soon as the first hardware prototypes are out.

For the rest of the stack I decided to go ahead with whatever is available in Debian stable. Why? Well, Raspbian provides a Debian stable-based image and I'm a Debian Developer, so things should go just natural for me in that front. Of course each component has its own packaging. I'm one of Debian's Qt maintainers then using Qt will also be quite natural for me. Plots? Qwt, of course. And with that I have most of my necessities fulfilled. I choose PostgreSql as database server and Mosquitto as MQTT broker.

Between the database and MQTT is mosimpa-datakeeper. The piece of software from which medical staff monitor patients is unsurprisingly called mosimpa-monitor.

MoSimPa's monitor main screen

mosimpa-monitor plots
Plots of a patient's data

Alarm thresholds setup

And for managing patients, devices, locations and internments (CRUD anyone?) there is currently a Qt-based application called mosimpa-abm.

ABM main screen

ABM internments view

The idea is to replace it with a web service so it doesn't needs to be confined to the RPi or require installations in other machines. I considered using webassembly but I would have to also build PostgreSql in order to compile Qt's plugin.

Translations? Of course! As I have already mentioned the code is written in English. Qt allows to easily translate applications, so I keep a Spanish one as the code changes (and we are primarily targeting spanish-speaking people). But of course this also means it can be easily translated to whichever language is necessary.

Even if I am a packager I still have some stuff to fix from the packaging itself, like letting datakeeper run with its own user. I just haven't got to it yet.


We are working towards getting the system certified by ANMAT, which is the Argentinian equivalent for EEUU's FDA.


While all the people involved are working ad-honorem funding is still required in order to buy materials, create the prototypes, etc. The project created payments links with Mercado Pago (in spanish and argentinian pesos) and other bank methods (PDF, also in spanish).

I repeat the links here with an aproximation to US$.

- 500 AR$ (less than 8 US$)
- 1000 AR$ (less than 15 US$)
- 2000 AR$ (less than 30 US$)
- 3000 AR$ (less than 45 US$)
- 5000 AR$ (less than 75 US$)

You can check the actual convertion rate in

The project was also presented at a funding call of argentinian Agencia de Promoci n de la Investigaci n, el Desarrollo Tecnol gico y la Innovaci n (Agencia I+D+i). 900+ projects where presented and 64 funded, MoSimPa between them.

30 March 2020

Mike Gabriel: UBports: Packaging of Lomiri Operating Environment for Debian (part 02)

Before and during FOSDEM 2020, I agreed with the people (developers, supporters, managers) of the UBports Foundation to package the Unity8 Operating Environment for Debian. Since 27th Feb 2020, Unity8 has now become Lomiri. Recent Uploads to Debian related to Lomiri Over the past 7-8 weeks the packaging progress has been slowed down due to other projects I am working on in parallel. However, quite a few things have been achieved: The packages qtsystems, qtfeedback, and qtpim are no official Qt5 components, and so I had to package Git snapshots of them; with all implicit consequences regarding ABI and API compatibilities, possibly Debian-internal library transitions, etc. Esp. packaging qtsystems was pretty tricky due to a number of failing unit tests when the package had been built in a clean chroot (like it is the case on Debian's buildd infrastructure). I learned a lot about DBus and DBus mocking while working on all those unit tests to finally pass in chrooted builds. Unfortunately, the Lomiri App Launch component still needs more work due to (finally only) one unit test (jobs-systemd) not always passing. Sometimes, the test gets stucks and then fails after having reached a time out. I'll add it to my list of those unreproducible build failures I have recently seen in several GTest related unit test scenarios. Sigh... Credits A great thanks goes to Lisandro Perez Meyer from the Debian KDE/Qt Team for providing an intro and help on Qt Debian packaging and an intro on symbols handling with C++ projects. Another big thanks goes to Dmitry Shachnev from the Debian KDE/Qt Team for doing a sponsored upload [1] of qtpim (and also a nice package review). Also a big thanks goes to Marius Gripsgard for his work on forking the first Lomiri components on the UBports upstream side. Previous Posts about my Debian UBports Team Efforts References

8 March 2020

Lisandro Dami n Nicanor P rez Meyer: Qt 4 removed from Debian Sid (unstable)

The day has finally arrived: Qt 4 is no longer part of Debian unstable. It's gone.

Thanks should go to many people. You know who you are, and I really appreciate the support and time you put into this. **Thanks**

13 October 2017

Lisandro Dami n Nicanor P rez Meyer: Qt 4 and 5 and OpenSSL1.0 removal

Today we received updates on the OpenSSL 1.0 removal status:


So those removal bugs' severities will be raised to RC in aproximately a month.

We still don't have any solutions for Qt 4 or 5.

For the Qt 5 case we will probably keep the bug open until Qt 5.10 is in the archive which should bring OpenSSL 1.1 support *or* FTP masters decide to remove OpenSSL1.0. In this last case the fate will be the same as with Qt4, below.

For Qt4 we do not have patches available and there will probably be none in time (remember we do not have upstream support). That plus the fact that we are actively trying to remove it from the archive it means we will remove openssl support. This might mean that apps using Qt4:

- Might cease to work.
- Might keep working:
- Informing their users that no SSL support is available programmer did a good job.
- Not informing their users that no SSL support is available and establishing connections non the less programmer might have not done a good job.

Trying to inform users as soon as possible,

Lisandro for the Qt/KDE team.

27 September 2017

Enrico Zini: Qt cross-architecture development in Debian

Use case: use Debian Stable as an environment to run amd64 development machines to develop Qt applications for Raspberry Pi or other smallish armhf devices. Qt Creator is used as Integrated Development Environment, and it supports cross-compiling, running the built source on the target system, and remote debugging. Debian Stable (vanilla or Raspbian) runs on both the host and the target systems, so libraries can be kept in sync, and both systems have access to a vast amount of libraries, with security support. On top of that, armhf libraries can be installed with multiarch also in the host machine, so cross-builders have access to the exact same libraries as the target system. This sounds like a dream system. But. We're not quite there yet. cross-compile attempts I tried cross compiling a few packages:
$ sudo debootstrap stretch cross
$ echo "strech_cross"   sudo tee cross/etc/debian_chroot
$ sudo systemd-nspawn -D cross
# dpkg --add-architecture armhf
# echo "deb-src stretch main" >> /etc/apt/sources.list
# apt update
# apt install --no-install-recommends build-essential crossbuild-essential-armhf
Some packages work:
# apt source bc
# cd bc-1.06.95/
# apt-get build-dep -a armhf .
# dpkg-buildpackage -aarmhf -j2 -b
dh_auto_configure -- --prefix=/usr --with-readline
        ./configure --build=x86_64-linux-gnu --prefix=/usr --includedir=\$ prefix /include --mandir=\$ prefix /share/man --infodir=\$ prefix /share/info --sysconfdir=/etc --localstatedir=/var --disable-silent-rules --libdir=\$ prefix /lib/arm-linux-gnueabihf --libexecdir=\$ prefix /lib/arm-linux-gnueabihf --disable-maintainer-mode --disable-dependency-tracking --host=arm-linux-gnueabihf --prefix=/usr --with-readline
dpkg-deb: building package 'dc-dbgsym' in '../dc-dbgsym_1.06.95-9_armhf.deb'.
dpkg-deb: building package 'bc-dbgsym' in '../bc-dbgsym_1.06.95-9_armhf.deb'.
dpkg-deb: building package 'dc' in '../dc_1.06.95-9_armhf.deb'.
dpkg-deb: building package 'bc' in '../bc_1.06.95-9_armhf.deb'.
 dpkg-genbuildinfo --build=binary
 dpkg-genchanges --build=binary >../bc_1.06.95-9_armhf.changes
dpkg-genchanges: info: binary-only upload (no source code included)
 dpkg-source --after-build bc-1.06.95
dpkg-buildpackage: info: binary-only upload (no source included)
With qmake based Qt packages, qmake is not configured for cross-building, probably because it is not currently supported:
# apt source pumpa
# cd pumpa-0.9.3/
# apt-get build-dep -a armhf .
# dpkg-buildpackage -aarmhf -j2 -b
        qmake -makefile -nocache "QMAKE_CFLAGS_RELEASE=-g -O2 -fdebug-prefix-map=/root/pumpa-0.9.3=.
          -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2"
          "QMAKE_CFLAGS_DEBUG=-g -O2 -fdebug-prefix-map=/root/pumpa-0.9.3=. -fstack-protector-strong
          -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2"
          "QMAKE_CXXFLAGS_RELEASE=-g -O2 -fdebug-prefix-map=/root/pumpa-0.9.3=. -fstack-protector-strong
          -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2"
          "QMAKE_CXXFLAGS_DEBUG=-g -O2 -fdebug-prefix-map=/root/pumpa-0.9.3=. -fstack-protector-strong
          -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2"
          "QMAKE_LFLAGS_RELEASE=-Wl,-z,relro -Wl,-z,now"
          "QMAKE_LFLAGS_DEBUG=-Wl,-z,relro -Wl,-z,now" QMAKE_STRIP=: PREFIX=/usr
qmake: could not exec '/usr/lib/x86_64-linux-gnu/qt5/bin/qmake': No such file or directory
debian/rules:19: recipe for target 'build' failed
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
With cmake based Qt packages it goes a little better in that it finds the cross compiler, pkg-config and some multiarch paths, but then it tries to run armhf moc, which fails:
# apt source caneda
# cd caneda-0.3.0/
# apt-get build-dep -a armhf .
# dpkg-buildpackage -aarmhf -j2 -b
          -DCMAKE_SYSTEM_PROCESSOR=arm -DCMAKE_C_COMPILER=arm-linux-gnueabihf-gcc
CMake Error at /usr/lib/arm-linux-gnueabihf/cmake/Qt5Core/Qt5CoreConfig.cmake:27 (message):
  The imported target "Qt5::Core" references the file
  but this file does not exist.  Possible reasons include:
  * The file was deleted, renamed, or moved to another location.
  * An install or uninstall procedure did not complete successfully.
  * The installation package was faulty and contained
  but not all the files it references.
Note: Although I improvised a chroot to be able to fool around with it, I would use pbuilder or sbuild to do the actual builds. Helmut suggests pbuilder --host-arch or sbuild --host. Doing it the non-Debian way This guide in the meantime explains how to set up a cross-compiling Qt toolchain in a rather dirty way, by recompiling Qt pointing it at pieces of the Qt deployed on the Raspberry Pi. Following that guide, replacing the CROSS_COMPILE value with /usr/bin/arm-linux-gnueabihf- gave me a working qtbase, for which it is easy to create a Kit for Qt Creator that works, and supports linking applications with Debian development packages that do not use Qt. However, at that point I need to recompile all dependencies that use Qt myself, and I quickly got stuck at that monster of QtWebEngine, whose sources embed the whole of Chromium. Having a Qt based development environment in which I need to become the maintainer for the whole Qt toolchain is not a product I can offer to a customer. Cross compiling qmake based packages on stretch is not currently supported, so at the moment I had to suggest to postpone all plans for total world domination for at least two years. Cross-building Debian In the meantime, Helmut Grohne has been putting a lot of effort into making Debian packages cross-buildable:
helmut> enrico: yes, cross building is painful. we have ~26000 source packages. of those, ~13000 build arch-dep packages. of those, ~6000 have cross-satisfiable build-depends. of those, I tried cross building ~2300. of those 1300 cross built. so we are at about 10% working. helmut> enrico: plus there are some 607 source packages affected by some 326 bugs with patches. helmut> enrico: gogo nmu them helmut> enrico: I've filed some 1000 bugs (most of them with patches) now. around 600 are fixed :)
He is doing it mostly alone, and I would like people not to be alone when they do a lot of work in Debian, so Join Helmut in the effort of making Debian cross-buildable! Build any Debian package for any device right from the comfort of your own work computer! Have a single development environment seamlessly spanning architecture boundaries, with the power of all that there is in Debian! Join Helmut in the effort of making Debian cross-buildable! Apply here, or join #debian-bootstrap on OFTC! Cross-building Qt in Debian mitya57 summarised the situation on the KDE team side:
mitya57> we have cross-building stuff on our TODO list, but it will likely require a lot of time and neither Lisandro nor I have it currently. mitya57> see for a summary of what needs to be done. mitya57> Any help or patches are always welcome :))
qemu-user-static Helmut also suggested to use qemu-user-static to make the host system able to run binaries compiled for the target system, so that even if a non-cross-compiling Qt build tries to run moc and friends in their target architecture version, they would transparently succeed. At that point, it would just be a matter of replacing compiler paths to point to the native cross-compiling gcc, and the build would not be slowed down by much. Fixing bug #781226 would help in making it possible to configure a multiarch version of qmake as the qmake used for cross compiling. I have not had a chance of trying to cross-build in this way yet. In the meantime... Having qtcreator able to work on an amd64 devel machine and deploy/test/debug remotely on an arm target machine, where both machine run debian stable and have libraries in sync, would be a great thing to have even though packages do not cross-build yet. Helmut summarised the situation on IRC:
svuorela and others repeat that Qt upstream is not compatible with Debian's multiarch thinking, in that Qt upstream insists on having one toolchain for each pair of architectures, whereas the Debian way tends to be to make packages generic and split stuff such that it can be mixed and matched. An example being that you need to run qmake (thus you need qmake for the build architecture), but qmake also embeds the relevant paths and you need to query it for them (so you need qmake for the host architecture) Either you run it through qemu, or you have a particular cross qmake for your build/host pair, or you fix qt upstream to stop this madness
Building qmake in Debian for each host-target pair, even just limited to released architectures, would mean building Qt 100 times, and that's not going to scale. I wonder:

15 August 2017

Lisandro Dami n Nicanor P rez Meyer: 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.

24 June 2017

Lisandro Dami n Nicanor P rez Meyer: 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.

22 February 2017

Lisandro Dami n Nicanor P rez Meyer: 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.