calibre 9 x11 vs wayland QT?

[gbm]

Under X11 get:
Without GPU

Worker Launch took: 0.00 seconds
GLX: Disable GBM because Ozone X11 is not available. Possibly caused by missing libraries for qpa-xcb support.

x11 with GPU

Worker Launch took: 0.00 seconds
GLX: Disable GBM because Ozone X11 is not available. Possibly caused by missing libraries for qpa-xcb support.
GBM is not supported with the current configuration. Fallback to Vulkan rendering in Chromium.

Using Wayland no errors.


When launching Viewer and Ebook editor.

Spoiler:

x11 no gpu

$ calibre-debug --gui
calibre 9.1  embedded-python: True
Linux-6.14.0-37-generic-x86_64-with-glibc2.39 Linux ('64bit', 'ELF')
('Linux', '6.14.0-37-generic', '#37~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov 20 10:25:38 UTC 2')
Python 3.14.2
Interface language: None
EXE path: /opt/calibre/bin/calibre-debug
Successfully initialized third party plugins: ACSM Input (0, 1, 0) && Gather KFX-ZIP (from KFX Input) (2, 29, 0) && DeDRM (10, 0, 9) && Package KFX (from KFX Input) (2, 29, 0) && ACSM Input Plugin GUI Extension (0, 1, 0) && Baen (1, 1, 1) && Barnes & Noble (1, 5, 7) && Diaps Editing Toolbag (0, 5, 0) && EpubMerge (3, 2, 0) && EpubSplit (3, 12, 0) && Goodreads (1, 8, 3) && KFX metadata reader (from KFX Input) (2, 29, 0) && From KFX (2, 29, 0) && KFX Input (2, 29, 0) && KindleUnpack - The Plugin (0, 83, 8) && Kobo Utilities (2, 25, 0) && Modify ePub (1, 8, 8)
QPA platform: xcb
devicePixelRatio: 1.09375
logicalDpi: 96.0 x 96.0
physicalDpi: 84.74714828897338 x 84.69527027027027
ApplicationPaletteChange event ignored
Using calibre Qt style: True
[0.00] Starting up...
System Color Scheme changed to: ColorScheme.Light
[0.00] Showing splash screen...
[1.07] splash screen shown
[1.07] Initializing db...
[1.31] db initialized
[1.31] Constructing main UI...
[2.12] [DEBUG] [koboutilities.config:<module>:72] CreateNewCustomColumn is supported
ACSM Input: GUI Plugin Genesis!
[2.30] [DEBUG] [koboutilities.action:KoboUtilitiesAction.genesis:117] Running in optimized mode
[2.74] GUI main window shown
EpubMerge: DEBUG: 2026-01-31 17:38:51,363: calibre_plugins.epubmerge.epubmerge_plugin(156): macmenuhack file_path:/home/username/.config/calibre/plugins/fanficfare_macmenuhack.txt
[2.79] [DEBUG] [koboutilities.config:get_library_config:635] library_config: {
    "SchemaVersion": 1,
    "profiles": {
        "Default": {
            "customColumnOptions": {
                "currentReadingLocationColumn": "",
                "lastReadColumn": "",
                "percentReadColumn": "",
                "ratingColumn": "rating",
                "restOfBookEstimateColumn": "",
                "timeSpentReadingColumn": ""
            },
            "forDevice": "*Any Device",
            "profileName": "Default",
            "storeOptionsStore": {
                "doNotStoreIfReopened": false,
                "promptToStore": true,
                "storeIfMoreRecent": false,
                "storeOnConnect": false
            },
            "updateOptionsStore": {
                "doEarlyFirmwareUpdate": false,
                "doFirmwareUpdateCheck": false,
                "firmwareUpdateCheckLastTime": 0
            }
        }
    },
    "readingPositionChangesStore": {
        "selectBooksInLibrary": false,
        "updeateGoodreadsProgress": false
    },
    "shelvesColumn": null
}
[2.79] [DEBUG] [koboutilities.action:KoboUtilitiesAction.device_driver_name:772] could not load extended driver. Exception= No module named 'calibre_plugins.kobotouch_extended'
[2.79] [DEBUG] [koboutilities.action:KoboUtilitiesAction.set_toolbar_button_tooltip:177] setting to text='Utilities to use with Kobo ereaders

Driver: KoboTouch'
[2.91] main UI initialized...
[2.91] Hiding splash screen
[2.91] splash screen hidden
[2.91] Started up in 2.91 seconds with 3961 books
Worker Launch took: 0.00 seconds
GLX: Disable GBM because Ozone X11 is not available. Possibly caused by missing libraries for qpa-xcb support.
Worker Launch took: 0.00 seconds
GLX: Disable GBM because Ozone X11 is not available. Possibly caused by missing libraries for qpa-xcb support.
margin:6: SyntaxWarning: "\s" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\s"? A raw string is also an option.
calibre_plugins.diaps_toolbag.resources.smartypants:567: SyntaxWarning: "\S" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\S"? A raw string is also an option.
calibre_plugins.diaps_toolbag.resources.smartypants:573: SyntaxWarning: "\S" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\S"? A raw string is also an option.
[31.28] Shutdown starting...
[31.28] Shutdown message shown...
[31.28] Grid view shutdown
[31.28] Bookshelf view shutdown
[31.29] Actions shutdown
[31.52] Various services shutdown
[31.52] Metadata backup shutdown
[31.53] Current database closed
[31.53] Windows hidden
[31.56] Waiting for overseers and live to shutdown
[31.56] Shutdown complete in 0.27, quitting...


x11 with gpu

~$ calibre-debug --gui
calibre 9.1  embedded-python: True
Linux-6.14.0-37-generic-x86_64-with-glibc2.39 Linux ('64bit', 'ELF')
('Linux', '6.14.0-37-generic', '#37~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov 20 10:25:38 UTC 2')
Python 3.14.2
Interface language: None
EXE path: /opt/calibre/bin/calibre-debug
Successfully initialized third party plugins: ACSM Input (0, 1, 0) && Gather KFX-ZIP (from KFX Input) (2, 29, 0) && DeDRM (10, 0, 9) && Package KFX (from KFX Input) (2, 29, 0) && ACSM Input Plugin GUI Extension (0, 1, 0) && Baen (1, 1, 1) && Barnes & Noble (1, 5, 7) && Diaps Editing Toolbag (0, 5, 0) && EpubMerge (3, 2, 0) && EpubSplit (3, 12, 0) && Goodreads (1, 8, 3) && KFX metadata reader (from KFX Input) (2, 29, 0) && From KFX (2, 29, 0) && KFX Input (2, 29, 0) && KindleUnpack - The Plugin (0, 83, 8) && Kobo Utilities (2, 25, 0) && Modify ePub (1, 8, 8)
QPA platform: xcb
devicePixelRatio: 1.09375
logicalDpi: 96.0 x 96.0
physicalDpi: 84.74714828897338 x 84.69527027027027
ApplicationPaletteChange event ignored
Using calibre Qt style: True
[0.00] Starting up...
System Color Scheme changed to: ColorScheme.Light
[0.00] Showing splash screen...
[1.08] splash screen shown
[1.08] Initializing db...
[1.21] db initialized
[1.21] Constructing main UI...
[2.02] [DEBUG] [koboutilities.config:<module>:72] CreateNewCustomColumn is supported
ACSM Input: GUI Plugin Genesis!
[2.21] [DEBUG] [koboutilities.action:KoboUtilitiesAction.genesis:117] Running in optimized mode
[2.60] GUI main window shown
EpubMerge: DEBUG: 2026-01-31 17:34:50,005: calibre_plugins.epubmerge.epubmerge_plugin(156): macmenuhack file_path:/home/username/.config/calibre/plugins/fanficfare_macmenuhack.txt
[2.63] [DEBUG] [koboutilities.config:get_library_config:635] library_config: {
    "SchemaVersion": 1,
    "profiles": {
        "Default": {
            "customColumnOptions": {
                "currentReadingLocationColumn": "#folder",
                "lastReadColumn": "",
                "percentReadColumn": "",
                "ratingColumn": "rating",
                "restOfBookEstimateColumn": "",
                "timeSpentReadingColumn": ""
            },
            "forDevice": null,
            "profileName": "Default",
            "storeOptionsStore": {
                "doNotStoreIfReopened": false,
                "promptToStore": true,
                "storeIfMoreRecent": false,
                "storeOnConnect": false
            },
            "updateOptionsStore": {
                "doEarlyFirmwareUpdate": false,
                "doFirmwareUpdateCheck": false,
                "firmwareUpdateCheckLastTime": 0
            }
        }
    },
    "readingPositionChangesStore": {
        "selectBooksInLibrary": false,
        "updeateGoodreadsProgress": false
    },
    "shelvesColumn": null
}
[2.63] [DEBUG] [koboutilities.action:KoboUtilitiesAction.device_driver_name:772] could not load extended driver. Exception= No module named 'calibre_plugins.kobotouch_extended'
[2.63] [DEBUG] [koboutilities.action:KoboUtilitiesAction.set_toolbar_button_tooltip:177] setting to text='Utilities to use with Kobo ereaders

Driver: KoboTouch'
[2.75] main UI initialized...
[2.75] Hiding splash screen
[2.75] splash screen hidden
[2.75] Started up in 2.75 seconds with 1327 books
[13.81] [DEBUG] [koboutilities.config:get_library_config:635] library_config: {
    "SchemaVersion": 1,
    "profiles": {
        "Default": {
            "customColumnOptions": {
                "currentReadingLocationColumn": "",
                "lastReadColumn": "",
                "percentReadColumn": "",
                "ratingColumn": "rating",
                "restOfBookEstimateColumn": "",
                "timeSpentReadingColumn": ""
            },
            "forDevice": "*Any Device",
            "profileName": "Default",
            "storeOptionsStore": {
                "doNotStoreIfReopened": false,
                "promptToStore": true,
                "storeIfMoreRecent": false,
                "storeOnConnect": false
            },
            "updateOptionsStore": {
                "doEarlyFirmwareUpdate": false,
                "doFirmwareUpdateCheck": false,
                "firmwareUpdateCheckLastTime": 0
            }
        }
    },
    "readingPositionChangesStore": {
        "selectBooksInLibrary": false,
        "updeateGoodreadsProgress": false
    },
    "shelvesColumn": null
}
[13.81] [DEBUG] [koboutilities.action:KoboUtilitiesAction.device_driver_name:772] could not load extended driver. Exception= No module named 'calibre_plugins.kobotouch_extended'
[13.81] [DEBUG] [koboutilities.action:KoboUtilitiesAction.set_toolbar_button_tooltip:177] setting to text='Utilities to use with Kobo ereaders

Driver: KoboTouch'
Worker Launch took: 0.00 seconds
GLX: Disable GBM because Ozone X11 is not available. Possibly caused by missing libraries for qpa-xcb support.
GBM is not supported with the current configuration. Fallback to Vulkan rendering in Chromium.
Worker Launch took: 0.00 seconds
GLX: Disable GBM because Ozone X11 is not available. Possibly caused by missing libraries for qpa-xcb support.
GBM is not supported with the current configuration. Fallback to Vulkan rendering in Chromium.
margin:6: SyntaxWarning: "\s" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\s"? A raw string is also an option.
calibre_plugins.diaps_toolbag.resources.smartypants:567: SyntaxWarning: "\S" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\S"? A raw string is also an option.
calibre_plugins.diaps_toolbag.resources.smartypants:573: SyntaxWarning: "\S" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\S"? A raw string is also an option.
[63.95] Shutdown starting...
[63.95] Shutdown message shown...
[63.95] Grid view shutdown
[63.95] Bookshelf view shutdown
[63.95] Actions shutdown
[64.19] Various services shutdown
[64.19] Metadata backup shutdown
[64.20] Current database closed
[64.20] Windows hidden
[64.22] Waiting for overseers and live to shutdown
[64.22] Shutdown complete in 0.27, quitting...


Wayland with gpu

$ calibre-debug --gui
calibre 9.1  embedded-python: True
Linux-6.14.0-37-generic-x86_64-with-glibc2.39 Linux ('64bit', 'ELF')
('Linux', '6.14.0-37-generic', '#37~24.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Nov 20 10:25:38 UTC 2')
Python 3.14.2
Interface language: None
EXE path: /opt/calibre/bin/calibre-debug
Successfully initialized third party plugins: ACSM Input (0, 1, 0) && Gather KFX-ZIP (from KFX Input) (2, 29, 0) && DeDRM (10, 0, 9) && Package KFX (from KFX Input) (2, 29, 0) && ACSM Input Plugin GUI Extension (0, 1, 0) && Baen (1, 1, 1) && Barnes & Noble (1, 5, 7) && Diaps Editing Toolbag (0, 5, 0) && EpubMerge (3, 2, 0) && EpubSplit (3, 12, 0) && Goodreads (1, 8, 3) && KFX metadata reader (from KFX Input) (2, 29, 0) && From KFX (2, 29, 0) && KFX Input (2, 29, 0) && KindleUnpack - The Plugin (0, 83, 8) && Kobo Utilities (2, 25, 0) && Modify ePub (1, 8, 8)
QPA platform: wayland
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 92.01509433962264 x 91.44
ApplicationPaletteChange event ignored
Using calibre Qt style: True
[0.00] Starting up...
[0.00] Showing splash screen...
System Color Scheme changed to: ColorScheme.Light
[1.07] splash screen shown
[1.07] Initializing db...
[1.30] db initialized
[1.30] Constructing main UI...
[2.13] [DEBUG] [koboutilities.config:<module>:72] CreateNewCustomColumn is supported
ACSM Input: GUI Plugin Genesis!
[2.32] [DEBUG] [koboutilities.action:KoboUtilitiesAction.genesis:117] Running in optimized mode
[2.78] GUI main window shown
EpubMerge: DEBUG: 2026-01-31 17:44:07,463: calibre_plugins.epubmerge.epubmerge_plugin(156): macmenuhack file_path:/home/username/.config/calibre/plugins/fanficfare_macmenuhack.txt
[2.82] [DEBUG] [koboutilities.config:get_library_config:635] library_config: {
    "SchemaVersion": 1,
    "profiles": {
        "Default": {
            "customColumnOptions": {
                "currentReadingLocationColumn": "",
                "lastReadColumn": "",
                "percentReadColumn": "",
                "ratingColumn": "rating",
                "restOfBookEstimateColumn": "",
                "timeSpentReadingColumn": ""
            },
            "forDevice": "*Any Device",
            "profileName": "Default",
            "storeOptionsStore": {
                "doNotStoreIfReopened": false,
                "promptToStore": true,
                "storeIfMoreRecent": false,
                "storeOnConnect": false
            },
            "updateOptionsStore": {
                "doEarlyFirmwareUpdate": false,
                "doFirmwareUpdateCheck": false,
                "firmwareUpdateCheckLastTime": 0
            }
        }
    },
    "readingPositionChangesStore": {
        "selectBooksInLibrary": false,
        "updeateGoodreadsProgress": false
    },
    "shelvesColumn": null
}
[2.82] [DEBUG] [koboutilities.action:KoboUtilitiesAction.device_driver_name:772] could not load extended driver. Exception= No module named 'calibre_plugins.kobotouch_extended'
[2.82] [DEBUG] [koboutilities.action:KoboUtilitiesAction.set_toolbar_button_tooltip:177] setting to text='Utilities to use with Kobo ereaders

Driver: KoboTouch'
[2.92] main UI initialized...
[2.92] Hiding splash screen
[2.92] splash screen hidden
[2.92] Started up in 2.92 seconds with 3961 books
Worker Launch took: 0.00 seconds
Worker Launch took: 0.00 seconds
margin:6: SyntaxWarning: "\s" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\s"? A raw string is also an option.
calibre_plugins.diaps_toolbag.resources.smartypants:567: SyntaxWarning: "\S" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\S"? A raw string is also an option.
calibre_plugins.diaps_toolbag.resources.smartypants:573: SyntaxWarning: "\S" is an invalid escape sequence. Such sequences will not work in the future. Did you mean "\\S"? A raw string is also an option.
[47.10] Shutdown starting...
[47.11] Shutdown message shown...
[47.11] Grid view shutdown
[47.11] Bookshelf view shutdown
[47.11] Actions shutdown
[47.35] Various services shutdown
[47.35] Metadata backup shutdown
[47.35] Current database closed
[47.35] Windows hidden
[47.38] Waiting for overseers and live to shutdown
[47.38] Shutdown complete in 0.28, quitting...

I can live with it at this time but is Qt gonna quit supporting X11 sometime in the future.

bernie

[dunhill]

Linux distributions are currently migrating to Wayland, but some have bugs, which we hope will be fixed soon.

[kovidgoyal]

That looks like some missing libraries. On my system running ebook viewer without GPU shows no errors and same with GPU under X11 and under Wayland. Probably the set of libraries needed by Qt WebEngine/Chromium has changed/increased.