Cura does not start, "QQmlApplicationEngine failed to load component"
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I have troubles getting Cura to start on my Gentoo system. I have had the same problem for v4.6.1, 4.8.0 and 4.9.0. The Python version I have built against has been 3.7 and 3.9, again with the same result regardless of the version. The output from Cura 4.9.0 built against Python 3.9.5 can be seen below.
$ cura /usr/lib/python3.7/site-packages/UM/PluginRegistry.py:4: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses import imp [MainThread] UM.Application.initialize [160]: Initializing Ultimaker Cura [MainThread] UM.Application.initialize [161]: App Version 4.9.0 [MainThread] UM.Application.initialize [162]: Api Version 7.5.0 [MainThread] UM.Application.initialize [163]: Build type ebuild [MainThread] UM.Resources.__initializeStoragePaths [446]: Initializing storage paths [MainThread] UM.Resources.__initializeStoragePaths [456]: Config storage path is /home/hrnick/.config/cura/4.9 [MainThread] UM.Resources.__initializeStoragePaths [464]: Data storage path is /home/hrnick/.local/share/cura/4.9 [MainThread] UM.Resources.__initializeStoragePaths [476]: Cache storage path is /home/hrnick/.cache/cura/4.9 [MainThread] UM.PackageManager.__init__ [54]: Found bundled packages JSON file: /usr/share/cura/resources/bundled_packages/cura.json [MainThread] UM.PackageManager.__init__ [54]: Found bundled packages JSON file: /usr/share/uranium/resources/bundled_packages/uranium.json Attribute Qt::AA_UseDesktopOpenGL must be set before QCoreApplication is created. [MainThread] UM.View.GL.OpenGLContext.detectBestOpenGLVersion [118]: Trying OpenGL context 4.1... [MainThread] UM.View.GL.OpenGLContext.detectBestOpenGLVersion [128]: Yay, we got at least OpenGL 4.1 core: 4.1 Core profile [MainThread] UM.Qt.QtApplication.initialize [175]: Detected most suitable OpenGL context version: 4.1 Core profile [MainThread] UM.Qt.QtApplication.initialize [182]: Initializing job queue ... [MainThread] UM.Qt.QtApplication.initialize [186]: Initializing version upgrade manager ... [MainThread] UM.PackageManager._loadManagementData [165]: Loaded bundled packages data from /usr/share/cura/resources/bundled_packages/cura.json [MainThread] UM.PackageManager._loadManagementData [165]: Loaded bundled packages data from /usr/share/uranium/resources/bundled_packages/uranium.json [MainThread] UM.PackageManager._loadManagementData [192]: Loaded user packages management file from /home/hrnick/.local/share/cura/4.9/packages.json [MainThread] UM.PackageManager._saveManagementData [265]: Package management file /home/hrnick/.local/share/cura/4.9/packages.json was saved [MainThread] UM.PluginRegistry.initializeBeforePluginsAreLoaded [117]: Loading plugin configuration file '/home/hrnick/.config/cura/4.9/plugins.json' Cyclic dependency detected between "file:///usr/share/cura/resources/qml/Actions.qml" and "file:///usr/share/cura/resources/qml/Actions.qml" QQmlApplicationEngine failed to load component WARNING: Cannot find style "default" - fallback: "/usr/lib64/qt5/qml/QtQuick/Controls/Styles/Desktop"What strikes me as odd is that "QQmlApplicationEngine failed to load component" does not specify what component can't be loaded and I don't really know where to start troubleshooting. Someone suggested that it might be related to "something between Python and Qt and/or PyQt itself" in the Gentoo bug report I filed and that it might be worth asking the QT community for tips and help. So that's what I'm doing now.
Have you any idea of what might be wrong or where and how I can start looking to get to the bottom with this? The Ultimaker Cura AppImage works but I would really like to figure out what's wrong here and use Cura installed through the Gentoo package manager. There seems to be at least a few other users who have run into the same problem as me.
Bug report at bugs.gentoo.org
Post on forums.gentoo.orgAny help would be highly appreciated! Thanks!
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I have troubles getting Cura to start on my Gentoo system. I have had the same problem for v4.6.1, 4.8.0 and 4.9.0. The Python version I have built against has been 3.7 and 3.9, again with the same result regardless of the version. The output from Cura 4.9.0 built against Python 3.9.5 can be seen below.
$ cura /usr/lib/python3.7/site-packages/UM/PluginRegistry.py:4: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses import imp [MainThread] UM.Application.initialize [160]: Initializing Ultimaker Cura [MainThread] UM.Application.initialize [161]: App Version 4.9.0 [MainThread] UM.Application.initialize [162]: Api Version 7.5.0 [MainThread] UM.Application.initialize [163]: Build type ebuild [MainThread] UM.Resources.__initializeStoragePaths [446]: Initializing storage paths [MainThread] UM.Resources.__initializeStoragePaths [456]: Config storage path is /home/hrnick/.config/cura/4.9 [MainThread] UM.Resources.__initializeStoragePaths [464]: Data storage path is /home/hrnick/.local/share/cura/4.9 [MainThread] UM.Resources.__initializeStoragePaths [476]: Cache storage path is /home/hrnick/.cache/cura/4.9 [MainThread] UM.PackageManager.__init__ [54]: Found bundled packages JSON file: /usr/share/cura/resources/bundled_packages/cura.json [MainThread] UM.PackageManager.__init__ [54]: Found bundled packages JSON file: /usr/share/uranium/resources/bundled_packages/uranium.json Attribute Qt::AA_UseDesktopOpenGL must be set before QCoreApplication is created. [MainThread] UM.View.GL.OpenGLContext.detectBestOpenGLVersion [118]: Trying OpenGL context 4.1... [MainThread] UM.View.GL.OpenGLContext.detectBestOpenGLVersion [128]: Yay, we got at least OpenGL 4.1 core: 4.1 Core profile [MainThread] UM.Qt.QtApplication.initialize [175]: Detected most suitable OpenGL context version: 4.1 Core profile [MainThread] UM.Qt.QtApplication.initialize [182]: Initializing job queue ... [MainThread] UM.Qt.QtApplication.initialize [186]: Initializing version upgrade manager ... [MainThread] UM.PackageManager._loadManagementData [165]: Loaded bundled packages data from /usr/share/cura/resources/bundled_packages/cura.json [MainThread] UM.PackageManager._loadManagementData [165]: Loaded bundled packages data from /usr/share/uranium/resources/bundled_packages/uranium.json [MainThread] UM.PackageManager._loadManagementData [192]: Loaded user packages management file from /home/hrnick/.local/share/cura/4.9/packages.json [MainThread] UM.PackageManager._saveManagementData [265]: Package management file /home/hrnick/.local/share/cura/4.9/packages.json was saved [MainThread] UM.PluginRegistry.initializeBeforePluginsAreLoaded [117]: Loading plugin configuration file '/home/hrnick/.config/cura/4.9/plugins.json' Cyclic dependency detected between "file:///usr/share/cura/resources/qml/Actions.qml" and "file:///usr/share/cura/resources/qml/Actions.qml" QQmlApplicationEngine failed to load component WARNING: Cannot find style "default" - fallback: "/usr/lib64/qt5/qml/QtQuick/Controls/Styles/Desktop"What strikes me as odd is that "QQmlApplicationEngine failed to load component" does not specify what component can't be loaded and I don't really know where to start troubleshooting. Someone suggested that it might be related to "something between Python and Qt and/or PyQt itself" in the Gentoo bug report I filed and that it might be worth asking the QT community for tips and help. So that's what I'm doing now.
Have you any idea of what might be wrong or where and how I can start looking to get to the bottom with this? The Ultimaker Cura AppImage works but I would really like to figure out what's wrong here and use Cura installed through the Gentoo package manager. There seems to be at least a few other users who have run into the same problem as me.
Bug report at bugs.gentoo.org
Post on forums.gentoo.orgAny help would be highly appreciated! Thanks!
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@hrnick check
file:///usr/share/cura/resources/qml/Actions.qmlit seems to include itself ?is it one of the modified files?
Thank you for your reply @J-Hilk!
I can't see this file referring to itself in the imports. Is there another way it could refer to itself?
$ head -n 15 /usr/share/cura/resources/qml/Actions.qml // Copyright (c) 2018 Ultimaker B.V. // Cura is released under the terms of the LGPLv3 or higher. pragma Singleton import QtQuick 2.10 import QtQuick.Controls 1.1 import QtQuick.Controls 2.3 as Controls2 import UM 1.1 as UM import Cura 1.0 as Cura Item { property alias newProject: newProjectAction; property alias open: openAction;I'm not sure what you are referring to by modified file, I haven't edited any files manually, they've been installed using Gentoo's package manager.
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Thank you for your reply @J-Hilk!
I can't see this file referring to itself in the imports. Is there another way it could refer to itself?
$ head -n 15 /usr/share/cura/resources/qml/Actions.qml // Copyright (c) 2018 Ultimaker B.V. // Cura is released under the terms of the LGPLv3 or higher. pragma Singleton import QtQuick 2.10 import QtQuick.Controls 1.1 import QtQuick.Controls 2.3 as Controls2 import UM 1.1 as UM import Cura 1.0 as Cura Item { property alias newProject: newProjectAction; property alias open: openAction;I'm not sure what you are referring to by modified file, I haven't edited any files manually, they've been installed using Gentoo's package manager.
@hrnick said in Cura does not start, "QQmlApplicationEngine failed to load component":
I'm not sure what you are referring to by modified file, I haven't edited any files manually, they've been installed using Gentoo's package manager.
oh, I'm sorry,
I miss read your post, I thought you wanted to apply a patch the the source code and therefore needed to build the application from source. But if I understand you correctly, you just want to build it yourself, no files changed/patched ?
where id you get your sources from, directly from GitHub?
https://github.com/Ultimaker/CuraI don't think I'll be much help, pyqt is not really my forte, maybe someone else has a better idea :(
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@hrnick said in Cura does not start, "QQmlApplicationEngine failed to load component":
I'm not sure what you are referring to by modified file, I haven't edited any files manually, they've been installed using Gentoo's package manager.
oh, I'm sorry,
I miss read your post, I thought you wanted to apply a patch the the source code and therefore needed to build the application from source. But if I understand you correctly, you just want to build it yourself, no files changed/patched ?
where id you get your sources from, directly from GitHub?
https://github.com/Ultimaker/CuraI don't think I'll be much help, pyqt is not really my forte, maybe someone else has a better idea :(
@J-Hilk said in Cura does not start, "QQmlApplicationEngine failed to load component":
oh, I'm sorry,
No worries. :)
I miss read your post, I thought you wanted to apply a patch the the source code and therefore needed to build the application from source. But if I understand you correctly, you just want to build it yourself, no files changed/patched ?
where id you get your sources from, directly from GitHub?
https://github.com/Ultimaker/CuraExactly, I just want to build, install and run the Gentoo portage version of Cura without any patches. The sources is downloaded from GitHub using Gentoo's package manager (I've tried with 4.9.1 now with the same result).
I don't think I'll be much help, pyqt is not really my forte, maybe someone else has a better idea :(
I appreciate your help regardless, I don't know where to start and I'm happy for any help I get, thanks!
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I enabled the debug use flag for a number of packages to see if that would give any clues.
$ cat /etc/portage/package.use/cura dev-qt/qtcore debug dev-qt/qtxml debug dev-qt/qtnetwork debug dev-qt/qttest debug dev-qt/qtgui debug dev-qt/qtwidgets debug dev-qt/qtdeclarative debug dev-qt/qtsvg debug dev-qt/qtopengl debug dev-qt/qtquickcontrols debug dev-qt/qtgraphicaleffects debug dev-qt/qtquickcontrols2 debug dev-python/uranium debug dev-python/PyQt5 debug media-gfx/cura debug usb zeroconfI don't know if there's anything useful being generated but here's a link to Cura output on pastebin.
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Finally some progress it seems, I've tried adding use flags to dependencies from the output. Compiling qtquickcontrols and qtquickcontrols2 with the widgets use flag got me past the QQmlApplicationEngine failed to load component message.
$ cat /etc/portage/package.use/cura
Debug
dev-qt/qtcore debug
dev-qt/qtxml debug
dev-qt/qtnetwork debug
dev-qt/qttest debug
dev-qt/qtgui debug
dev-qt/qtwidgets debug
dev-qt/qtdeclarative debug
dev-qt/qtsvg debug
dev-qt/qtopengl debug
dev-qt/qtquickcontrols debug
dev-qt/qtgraphicaleffects debug
dev-qt/qtquickcontrols2 debug
dev-python/uranium debug
dev-python/PyQt5 debug
media-gfx/cura debugRemoves some error messages
media-gfx/cura usb zeroconf
Try to find missing use flags #1, does not seem to help
dev-qt/qtgui dbus
dev-qt/qtwidgets gtkTry to find missing use flags #2, "Fatal Python error: Aborted" when starting cura
dev-qt/qtquickcontrols widgets
dev-qt/qtquickcontrols2 widgetsNow I get a clear error message, "Fatal Python error: Aborted" at least.
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Solved it, dev-qt/qtquickcontrols needs to be build with USE="widgets". Also PyQt5 must not be built with the debug flag enabled.
