HOWTO: Installing Qt and building SavvyCAN on Linux

[douglasheld2]

1. Browse to Qt's developer Wiki site. Here, you can create an account without needing to verify a telephone number: https://wiki.qt.io/Qt_Serial_Port

2. On that Wiki page, click on Log In in the upper right. This will land you on login.qt.io/login, the Unified Qt identity page. Click the green "New Account" link.

3. Enter your email address, new password twice, the captcha, and accept the terms.

4. Receive the verification email and click the link.

5. Set a friendly name for the account

6. Browse to the Open Source installer page: https://www.qt.io/download-qt-installer-oss
   Note this is not the big glossy "download" link from the home page.

7. Click the icon and then the download button which is beneath

8. If you are using Chrome and you download the installer for Linux, it will block your download because of the filename extension, "run". Click in the downloads to indicate to Chrome that you wish to accept the file.

9. In the terminal, navigate to your browser's Downloads directory and issue chmod +x qt-online-installer-linux-x64-4.8.0.run or specify whatever is the name of the QT installer you downloaded.
   Note further, the version number of the installer - 4.8.0 in my case - is not the same as the version of Qt libraries you are going to download. Today I am downloading version 6.7.2 but I don't find that out until later.

10. In the terminal, now run the installer, e.g. ./qt-online-installer-linux-x64-4.8.0.run

11. In the graphical installer window, log in with the credentials you created in step 3. Proceed Next.

12. Click the first checkbox when you agree to the licenses.
    

13. Click the second checkbox to indicate you are an individual and are not using Qt for work. Proceed Next.

14. You are now presented with an install type. I don't dare choose "custom install" but someone help me here. Choose "Qt ... for Desktop Development"
    

15. Accept the default installation path of Qt in your home directory (as I have seen that path referenced in the SavvyCAN build instructions). Proceed Next.

16. The installer will install all components after a few minutes of work.

17. It will offer to open the Qt Design Studio and Qt Creator applications. Because now is the ideal time to understand whether anything is not working, I'd advise to select all such boxes. Proceed clicking "Finish".

18. Note, in my distro (ElementaryOS 7.1) the usr/bin/xmessage application has opened a window, with an error message relating to the Qt system requirements not being met at runtime. Neither of the GUI applications have actually opened.
    
    "From 6.5.0, xcb-cursor0 or libxcb-cursor0 is needed to load the Qt xcb platform plugin...."

19. Just on the off chance that you are running Ubuntu and have the same error and it will become important to us later, I'll follow up with the following command:

20. sudo apt install libxcb-cursor0

21. I can then verify with the following command to start one of the Qt graphical applications: ~/Qt/Tools/QtCreator/bin/qtcreator

22. For my installation, the application opened and I take this as a sign that Qt graphical applications can work now.

PART TWO: Building SavvyCAN Dependencies

23. Now in the terminal, change to your home directory.
24. Type git clone https://github.com/collin80/SavvyCAN.git
25. Change into the SavvyCAN directory... cd Savv*
26. Type git checkout tags/continuous-QT6 and then git fetch
27. We are now going to build this with qmake and that is a Qt application. Just ensure it is not already installed outside of what we just did up to step 22 above. Run the command which qmake and we are expecting to see, no response.
28. In my case, I have a conflicting, older, version of Qt and I want to get rid of it! I've run sudo apt autopurge qtchooser and that seems to have done the trick - but YMMV. For good measure, I also had to purge cmake.
29. Now we need to set the path for building. export PATH=~/Qt/6.7.2/gcc_64/bin:$PATH
30. Now try the build: qmake. At this point, we expect the error, "Project ERROR: Unknown modules in QT: serialbus serialport"
31. Return to the web browser and go to https://download.qt.io/official_releases/qt/6.7/6.7.2/submodules/ . Change up a directory and choose the correct version, if necessary. I am downloading version 6.7.2. today. Download both serialport-*.zip and serialbus-*.zip.
32. In the terminal, change to your Downloads directory and unzip qtserialport first. (Note I think the author of the link above has the dependencies switched around) Change to the extracted directory.
33. Now add Qt's version of CMake to the PATH: export PATH=~/Qt/Tools/CMake/bin:$PATH
34. Next add Qt's version of Ninja to the PATH: export PATH=~/Qt/Tools/Ninja/bin:$PATH
35. Thanks to https://www.tal.org/tutorials/building-qt-62-sub-modules for the following instructions: run qt-configure-module . which will conclude by indicating it has written the configuration files.
36. Run cmake --build . --parallel 4. Note, the parallel build setting is your option. If something breaks, try without the parallel parameter.
37. Run cmake --install .. which is a good sign - it has automatically detected where we have already installed Qt and it is enhancing that installation - exactly what we want.
38. Now repeat the same steps 32 - 38 for serialbus
39. Note, when you run the configure command for serialbus, it will conclude with "Qt Serial Bus: Socket CAN... yes" and "Serial port... yes".
40. Note, when you run the install command for serialbus you may notice in the output it installs files like ~/Qt/6.7.2/gcc_64/plugins/canbus/libqtpeakcanbus.so which is a great sign.

PART THREE: BUILDING and running SavvyCAN

42. Returning to step 25, enter the SavvyCAN directory and type qmake, which doesn't return anything when the command is successful. Just exit code 0.
43. When running the next command I got an error, GL/gl.h no such file or directory and this was solved by sudo apt install libgl-dev. Ignore this if you don't get the error.
44. Next is to run make. This compiles all the parts of SavvyCAN. It takes 22 minutes on my slow computer.
45. aaand.... run ./SavvyCAN to run SavvyCAN.