Arch Linux

andrew7

Member

Registered: 2022-02-07

Posts: 3

[SOLVED]No Text Display on Zeal and Calibre[ebook-viewer]

System info:

OS: Arch Linux
Kernel: x86_64 Linux 6.14.4-arch1-1
Resolution: No X Server
DE: Xfce4
WM: Xfwm4
CPU: Intel Core i5-2500 @ 4x 3.7GHz [71.0°C]
GPU: NVIDIA GeForce GT 710 [v 470.256.02 ]
RAM: 15941MiB

Getting Errors from Zeal and Calibre ebook-viewer Apps

$ ebook-viewer Quick\ Start\ Guide\ -\ John\ Schember.epub
Backend texture is not a Vulkan texture.
Compositor returned null texture

same on Zeal

Last edited by andrew7 (2025-05-02 17:21:56)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,076

Re: [SOLVED]No Text Display on Zeal and Calibre[ebook-viewer]

Your HW can't do vulkan properly. Export GSK_RENDERER=ngl (or maybe even better gl) globally: https://wiki.archlinux.org/title/GTK#GT … s_are_slow

tekstryder

Member

Registered: 2013-02-14

Posts: 505

Re: [SOLVED]No Text Display on Zeal and Calibre[ebook-viewer]

or maybe even better gl

Not sure either of those apps use GTK, but FYI... the old GL renderer is no longer available. It was deprecated as of the GTK 4.18 release cycle. NGL is the only non-Vulkan GL rendering backend now.

arojas

Developer

From: Spain

Registered: 2011-10-09

Posts: 2,275

Re: [SOLVED]No Text Display on Zeal and Calibre[ebook-viewer]

zeal and calibre are Qt, not GTK

QTWEBENGINE_CHROMIUM_FLAGS="--use-gl=desktop"

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,076

Re: [SOLVED]No Text Display on Zeal and Calibre[ebook-viewer]

Ah whoops sorry. Newer enough chromium/webengine officially defaulting to vulkan now?

andrew7

Member

Registered: 2022-02-07

Posts: 3

Re: [SOLVED]No Text Display on Zeal and Calibre[ebook-viewer]

Thank you pointing these flags

QTWEBENGINE_CHROMIUM_FLAGS="--use-gl=desktop"

using the "desktop" flag creates core dump

QTWEBENGINE_CHROMIUM_FLAGS="--use-gl=disabled"

lets me use both the apps