No such plugin: 'peakcan'

rzucca

Hi!

I'm writing a program to flash firmware on a power module via CAN with peakcan.

It works fine when I start it from Qt Creator

10:51:09: Starting C:/Git/AB_Flasher/10_Dev/flasher/build-flasher_qt-Desktop_Qt_6_4_0_MinGW_64_bit-Release/release/flasher_qt.exe...
qt.canbus.plugins.peakcan: Using PCAN-API version: 4.6.1.728

But if I make a standalone app with windeployqt, it is unable to find the plugins

10:53:29: Starting C:/Git/AB_Flasher/10_Dev/flasher/build-flasher_qt-Desktop_Qt_6_4_0_MinGW_64_bit-Release/release/flasher_qt.exe...
"No such plugin: 'peakcan'"

I'm using the following script to make the standalone application:

set PATH=C:\Qt\6.4.0\mingw_64\bin;C:\Qt\Tools\mingw1120_64\bin;%PATH%
cd /D C:\Qt\6.4.0\mingw_64
.\bin\windeployqt.exe --plugindir $(TargetDir)\plugins C:\Git\AB_Flasher\10_Dev\flasher\build-flasher_qt-Desktop_Qt_6_4_0_MinGW_64_bit-Release\release
.\bin\windeployqt.exe --libdir $(TargetDir)\lib C:\Git\AB_Flasher\10_Dev\flasher\build-flasher_qt-Desktop_Qt_6_4_0_MinGW_64_bit-Release\release

This adds .dll's and subdirectories as expected, including a canbus subdirectory, containing

-a----        23/09/2022     05:42          82880 qtpassthrucanbus.dll
-a----        23/09/2022     05:42          64448 qtpeakcanbus.dll
-a----        23/09/2022     05:42          56256 qtsysteccanbus.dll
-a----        23/09/2022     05:42          56768 qttinycanbus.dll
-a----        23/09/2022     05:42          60352 qtvectorcanbus.dll
-a----        23/09/2022     05:42          63424 qtvirtualcanbus.dll

Every time the file Qt6Core.dll is present in the release directory the program fails to find the plugins. If Qt6Core.dll is removed, the plugins are found. But then I can start my application only through QT creator

Qt version and make environments I am using can be deduced from the name of my build directory, If you need more information please ask

I got lost in the Qt documentation regarding plugins because they are much too advanced and abstract for me, lacking any concrete example pertaining PeakCAN

Some help would be highly appreciated

jsulm

@rzucca said in No such plugin: 'peakcan':

subdirectories as expected

What is inside plugins subfolder in deployed application?

rzucca

No plugins subfolder is created.

jsulm

@rzucca That explains your problem

rzucca

Some explanations regarding the solution would be also highly appreciated

Surely I'm overseeing something and/or making some mistake. I'd like to find out what.

And above all, how to solve it

jsulm

@rzucca https://doc.qt.io/qt-6/windows-deployment.html explains how plug-in should be deployed. If no plug-ins where deployed with windeployqt then something went wrong.

rzucca

Believe me, I read this page many times, and even understood some of it.

I couldn't understand how to build Qt statically, nor how to use the Q_IMPORT_PLUGIN() Macro

Sorry for the delay in my answer, I'm only allowed to post something every 10 minutes

jsulm

@rzucca said in No such plugin: 'peakcan':

I couldn't understand how to build Qt statically

No need to build Qt statically and also Q_IMPORT_PLUGIN should not be needed.
All you need to do is to deploy needed plugins as shown in "Creating the Application Package" part of the link.

rzucca

Any suggestions about how to do that? Because windeployqt isn't doing it

jsulm

@rzucca You still can create subfolders by yourself and copy plug-ins there.

rzucca

That's great news, thanks!

I just would like to know which plug-ins I need and where to find them

jsulm

@rzucca said in No such plugin: 'peakcan':

I just would like to know which plug-ins I need

Depends on what app is using, on what platform, ...
Where to find: in your Qt installation.
Apparently you also need peakcan plug-in.

rzucca

Well, I'm using QT 6.4 on Windows 10. I think I just need the peakcan plug-in.

I already tried to copy the PCANBasic.dll to an handmade plugins subfolder, but to no avail. That's evidently not the component I'm looking for. The plug-in I need must be in the Qt folder, I guess, because Qt Creator can find it

I'm not (consciously) using any other external plug-ins or libraries. Am I missing any important piece of information?

rzucca

@jsulm There are three subfolders of Qt called plugin canbus. Their content seems to be identical, and the same that is added by windeployqt to the canbus subdirectory.

I tried to copy their content to a manually created plugin subfolder in the release, but to no avail

I am still stuck: I know that I must add some plugins to the release, but I still don't know what plugins, or where to find them