It turned out to be an authorization issue which was solved by "xhost +"
for the non-root user. Calibre is still not doing the PDF conversion,
but the problem is with the plugin for that conversion not the Debian
environment. This can be closed.
On Wed, 15 Jun 2022 13:39:24 +0900 yokota <yokota.h...@gmail.com> wrote:
> Hello,
>
> > 2. If I run as a non-root user I get:
> >
> > Authorization required, but no authorization protocol specified
> > qt.qpa.xcb: could not connect to display :0.0
> > qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in ""
even though it
> > was found.
> > This application failed to start because no Qt platform plugin could be
> > initialized. Reinstalling the application may fix this problem.
> >
> > Available platform plugins are: eglfs, linuxfb, minimal,
minimalegl, offscreen,
> > vnc, wayland-egl, wayland, wayland-xcomposite-egl,
wayland-xcomposite-glx, xcb.
>
> > qt.qpa.xcb: could not connect to display :0.0
> This line shows that you are not connected to X11.
>
> PDF render uses Qt library, and Qt requires some GUI environment like
X11.
> Check X11 environment and works other X11 client programs on your
machine.
>
> You must setup X11 and connect X server properly even if you don't
> want to use GUI.
> Install X11 environment and related Qt libraries, and run from GUI
environment.
>
> --
> YOKOTA
>
>
