hmm - should work out of the box - at least i noticed a policykit window popping up - might be that some settings are needed to be able to elevate the rights for the user. There are two choices i would test: sudo and pkexec - as far as i remember i only installed flatpak and was done with. ok, i'm in sudoers.d.
agaida@ramme ~ % flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
agaida@ramme ~ % flatpak remotes
Name Options
flathub system
gnome system
org.tabos.roger-origin system,no-enumerate
1 agaida@ramme ~ % flatpak install flathub org.kde.krita :(
Erforderliche Laufzeit für org.kde.krita/x86_64/stable (org.kde.Platform/x86_64/5.10) ist nicht installiert. Suche läuft …
Found in remote flathub, do you want to install it? [y/n]: y
Installieren: org.kde.Platform/x86_64/5.10 von flathub
[####################] 12 delta parts, 63 loose fetched; 305501 KiB transferred in 19 seconds
Installieren: org.freedesktop.Platform.GL.nvidia-390-59/x86_64/1.4 von flathub
[####################] Downloading: 47,7 MB/47,7 MB (15,9 MB/s)
Installieren: org.freedesktop.Platform.ffmpeg/x86_64/1.6 von flathub
[####################] 1 delta parts, 2 loose fetched; 2649 KiB transferred in 0 seconds
Installieren: org.kde.KStyle.Adwaita/x86_64/5.10 von flathub
[####################] 1 delta parts, 2 loose fetched; 351 KiB transferred in 0 seconds
Installieren: org.kde.Platform.Locale/x86_64/5.10 von flathub
[####################] 5 delta parts, 128 loose fetched; 100454 KiB transferred in 6 seconds
Installieren: org.kde.krita/x86_64/stable von flathub
[####################] 3 delta parts, 30 loose fetched; 95465 KiB transferred in 5 seconds
Installieren: org.kde.krita.Locale/x86_64/stable von flathub
[####################] 1 delta parts, 1 loose fetched; 2046 KiB transferred in 0 seconds
flatpak install flathub org.kde.krita 40,24s user 13,07s system 45% cpu 1:56,61 total
So it should not be rocket science. But i might be mistaken and will test it with a fresh LXQt build in kvm
Last but not least run the program
1 agaida@ramme ~ % flatpak run org.kde.krita
Setting XDG_DATA_DIRS "/app/bin/../share:/app/share:/usr/share:/usr/share/runtime/share:/run/host/share"
Override language: ""
OpenGL Info
Vendor: VMware, Inc.
Renderer: "llvmpipe (LLVM 6.0, 128 bits)"
Version: "3.0 Mesa 18.0.2"
Shading language: 1.30
Requested format: QSurfaceFormat(version 3.0, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::SwapBehavior(DoubleBuffer), swapInterval 0, colorSpace QSurfaceFormat::ColorSpace(DefaultColorSpace), profile QSurfaceFormat::OpenGLContextProfile(CompatibilityProfile))
Current format: QSurfaceFormat(version 3.0, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 0, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::SwapBehavior(DoubleBuffer), swapInterval 0, colorSpace QSurfaceFormat::ColorSpace(DefaultColorSpace), profile QSurfaceFormat::OpenGLContextProfile(NoProfile))
Version: 3.0
Supports deprecated functions true
is OpenGL ES: false
krita has opengl true
Available translations QSet("bg", "oc", "mk", "hu", "nl", "ko", "be", "ru", "th", "da", "ia", "sl", "en_US", "gl", "pt_BR", "sk", "ro", "cs", "ms", "ca@valencia", "it", "eo", "el", "kk", "tg", "bs", "nb", "sv", "ast", "cy", "lv", "fa", "pt", "uz", "zh_CN", "es", "tr", "pl", "fi", "br", "ga", "de", "ca", "vi", "xh", "hne", "fy", "he", "en_GB", "ug", "sq", "mai", "wa", "pa", "ar", "mr", "se", "fr", "ja", "ta", "hi", "et", "lt", "is", "eu", "uk", "uz@cyrillic", "zh_TW", "hr", "af", "km", "nds", "ne", "nn")
Available domain translations QSet("bg", "oc", "mk", "hu", "nl", "ko", "be", "ru", "th", "da", "ia", "sl", "en_US", "gl", "pt_BR", "sk", "ro", "cs", "ms", "ca@valencia", "it", "eo", "el", "kk", "tg", "bs", "nb", "sv", "ast", "cy", "lv", "fa", "pt", "uz", "zh_CN", "es", "tr", "pl", "fi", "br", "ga", "de", "ca", "vi", "xh", "hne", "fy", "he", "en_GB", "ug", "sq", "mai", "wa", "pa", "ar", "mr", "se", "fr", "ja", "ta", "hi", "et", "lt", "is", "eu", "uk", "uz@cyrillic", "zh_TW", "hr", "af", "km", "nds", "ne", "nn")
Qt UI languages ("de-DE") "de_DE.utf8"
input profiles were read from ' /app/share/krita/input '.
Loading Python plugin
Python::setPath. Script paths: ("/home/agaida/.var/app/org.kde.krita/data/krita/", "/app/share/krita/", "/home/agaida/.var/app/org.kde.krita/data/krita/pykrita/", "/app/share/krita/pykrita/", "/app/share/pykrita/") false
pythonLibsPath (krita-python-libs) "/app/lib/krita-python-libs"
Found krita-python-libs at "/app/lib/krita-python-libs"
pythonLibsPath (sip) ""
Setting python paths: "/home/agaida/.var/app/org.kde.krita/data/krita/:/app/share/krita/:/home/agaida/.var/app/org.kde.krita/data/krita/pykrita/:/app/share/krita/pykrita/:/app/share/pykrita/:/app/lib/krita-python-libs:/app/lib/python3/dist-packages"
/app/lib/krita-python-libs/krita added to PYTHONPATH
Button KoToolBoxButton(0xc1663f0, name="SvgTextTool") has a conflicting priority
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Regular")
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Bold")
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Regular")
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Regular")
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Regular")
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Light")
krita.general: Could not find font QVariant(QString, "Source Sans Pro") with style QVariant(QString, "Regular")
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/edit-clear
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/zoom-in
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/opacity-decrease
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/opacity-increase
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/lightness-increase
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/lightness-decrease
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/rotate-canvas-left
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/rotation-reset
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/rotate-canvas-right
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/zoom-out
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/brushsize-decrease
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/brushsize-increase
file:///app/lib/qml/org/krita/sketch/components/Button.qml:84:9: QML Image: Failed to get image from provider: image://icon/preset-switcher
QXcbConnection: XCB error: 3 (BadWindow), sequence: 1174, resource id: 5236348, major code: 40 (TranslateCoords), minor code: 0
agaida@ramme ~ %
So - seems to work.