QT Error with Calibre 5.8.1 but not with Calibre 4.23.0

andrew.46 · 12-28-2020, 03:56 AM

I am happily running Calibre 4.15 and I was looking at installing and running the latest version on 64bit Slackware Linux: 5.8.1. However when using the binary provided from the Calibre site for 5.8.1 I get the following segmentation fault:

Code:

andrew@ilium~/tmp/calibre5$ ./calibre
qt.qpa.xcb: xcb_shm_create_segment() can't be called for size 17178820624, maximumallowed size is 4294967295
Segmentation fault
andrew@ilium~/tmp/calibre5$

For curiosity I also downloaded the binary from the Calibre web site for the last of the 4.x series: 4.23.0 and this ran without error. Curious...

My suspicion is that is perhaps a local system error rather than a Calibre error (and I have posted on the Slackware Forums as well to cover this possibility) but I am posting here in case any wise Calibre users can give a steer.

kovidgoyal · 12-28-2020, 06:58 AM

Get a backtrace for the segfault, that might be more illuminating.

andrew.46 · 12-28-2020, 08:20 PM

Quote:

Originally Posted by kovidgoyal

Get a backtrace for the segfault, that might be more illuminating.

Thanks for looking at this issue, which appears to not be affecting other Slackware users! Below is the backtrace which I give complete (as I am not sure what is relevant):

Code:

andrew@ilium~/tmp/calibre5$ gdb ./calibre
GNU gdb (GDB) 10.1
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-slackware-linux".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./calibre...
(No debugging symbols found in ./calibre)
(gdb) run
Starting program: /home/andrew/tmp/calibre5/calibre 
process 4474 is executing new program: /home/andrew/tmp/calibre5/bin/calibre
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
[New Thread 0x7fffe49c9700 (LWP 4478)]
[New Thread 0x7fffdc505700 (LWP 4479)]
[New Thread 0x7fffdbd04700 (LWP 4480)]
[New Thread 0x7fffdb503700 (LWP 4481)]
[New Thread 0x7fffdad02700 (LWP 4482)]
[Detaching after fork from child process 4483]
[New Thread 0x7fffda0d3700 (LWP 4484)]
[Detaching after fork from child process 4485]
[Thread 0x7fffda0d3700 (LWP 4484) exited]
[Detaching after fork from child process 4486]
Failed to initialize plugin: '/home/andrew/.config/calibre/plugins/DeDRM.zip'
[New Thread 0x7fffda0d3700 (LWP 4488)]
[New Thread 0x7fffc200c700 (LWP 4489)]
[New Thread 0x7fffc180b700 (LWP 4490)]
[New Thread 0x7fffc100a700 (LWP 4491)]
[New Thread 0x7fffc0809700 (LWP 4492)]
[New Thread 0x7fffb3fff700 (LWP 4493)]
[New Thread 0x7fffb37fe700 (LWP 4494)]
[New Thread 0x7fffb2ffd700 (LWP 4495)]
[New Thread 0x7fffb27fc700 (LWP 4496)]
[New Thread 0x7fffb1ffb700 (LWP 4497)]
[New Thread 0x7fffb17fa700 (LWP 4498)]
[New Thread 0x7fffb0ff9700 (LWP 4499)]
[New Thread 0x7fff93fff700 (LWP 4500)]
[New Thread 0x7fff937fe700 (LWP 4501)]
[New Thread 0x7fff92ffd700 (LWP 4502)]
[New Thread 0x7fff927fc700 (LWP 4503)]
[New Thread 0x7fff91ffb700 (LWP 4504)]
[New Thread 0x7fff917fa700 (LWP 4505)]
[New Thread 0x7fff90ff9700 (LWP 4506)]
[New Thread 0x7fff73fff700 (LWP 4507)]
[New Thread 0x7fff737fe700 (LWP 4508)]
[New Thread 0x7fff72ffd700 (LWP 4509)]
[New Thread 0x7fff727fc700 (LWP 4510)]
[New Thread 0x7fff71ffb700 (LWP 4511)]
[New Thread 0x7fff717fa700 (LWP 4512)]
[New Thread 0x7fff70ff9700 (LWP 4513)]
[New Thread 0x7fff53fff700 (LWP 4514)]
[New Thread 0x7fff537fe700 (LWP 4515)]
qt.qpa.xcb: xcb_shm_create_segment() can't be called for size 17178820624, maximumallowed size is 4294967295
--Type <RET> for more, q to quit, c to continue without paging--q
Quit
(gdb) bt
#0  0x00007ffff7c77501 in __memmove_avx_unaligned_erms () from /lib64/libc.so.6
#1  0x00007fffe604b6e8 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5XcbQpa.so.5
#2  0x00007fffe604b899 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5XcbQpa.so.5
#3  0x00007fffe604c2f9 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5XcbQpa.so.5
#4  0x00007fffe604bcf9 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5XcbQpa.so.5
#5  0x00007fffec9898d7 in QBackingStore::flush(QRegion const&, QWindow*, QPoint const&) () from /home/andrew/tmp/calibre5/lib/libQt5Gui.so.5
#6  0x00007fffeb48ef5f in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#7  0x00007fffeb49003a in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#8  0x00007fffeb49296a in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#9  0x00007fffeb493060 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#10 0x00007fffeb4bc9ef in QWidgetPrivate::syncBackingStore() () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#11 0x00007fffeb4dc4fd in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#12 0x00007fffeb4dff63 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#13 0x00007fffeb48236c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#14 0x00007fffeb4893e0 in QApplication::notify(QObject*, QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#15 0x00007fffebd4816e in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtWidgets.so
#16 0x00007fffedc70350 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#17 0x00007fffec7c113c in QGuiApplicationPrivate::processGeometryChangeEvent(QWindowSystemInterfacePrivate::GeometryChangeEvent*) ()
   from /home/andrew/tmp/calibre5/lib/libQt5Gui.so.5
#18 0x00007fffec7c596d in QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) ()
   from /home/andrew/tmp/calibre5/lib/libQt5Gui.so.5
#19 0x00007fffec79faab in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from /home/andrew/tmp/calibre5/lib/libQt5Gui.so.5
#20 0x00007fffe6057eaa in ?? () from /home/andrew/tmp/calibre5/lib/libQt5XcbQpa.so.5
#21 0x00007fffeea3ea1e in g_main_context_dispatch () from /home/andrew/tmp/calibre5/lib/libglib-2.0.so.0
#22 0x00007fffeea3eca8 in ?? () from /home/andrew/tmp/calibre5/lib/libglib-2.0.so.0
#23 0x00007fffeea3ed5c in g_main_context_iteration () from /home/andrew/tmp/calibre5/lib/libglib-2.0.so.0
#24 0x00007fffedccf41c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
--Type <RET> for more, q to quit, c to continue without paging--
#25 0x00007fffeb6289a0 in QSplashScreen::repaint() () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#26 0x00007fffebb5e57e in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtWidgets.so
#27 0x00007ffff76e0746 in PyCFunction_Call () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#28 0x00007ffff76a31d0 in _PyObject_MakeTpCall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#29 0x00007ffff773428a in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#30 0x00007ffff76d740a in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#31 0x00007ffff77339ba in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#32 0x00007ffff76d740a in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#33 0x00007ffff77339ba in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#34 0x00007ffff76d740a in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#35 0x00007ffff77339ba in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#36 0x00007ffff76d740a in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#37 0x00007ffff77339ba in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#38 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#39 0x00007ffff76d7183 in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#40 0x00007ffff76d767c in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#41 0x00007ffff76beefd in PyVectorcall_Call () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#42 0x00007fffee1dbe05 in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtCore.so
#43 0x00007fffee1dc338 in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtCore.so
#44 0x00007fffee1dc5c0 in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtCore.so
#45 0x00007fffee1dd0f7 in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtCore.so
#46 0x00007fffedcaaf97 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#47 0x00007fffedcafcb3 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#48 0x00007fffedca2003 in QObject::event(QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#49 0x00007fffeb48236c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#50 0x00007fffeb4893e0 in QApplication::notify(QObject*, QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Widgets.so.5
#51 0x00007fffebd4816e in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtWidgets.so
#52 0x00007fffedc70350 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
--Type <RET> for more, q to quit, c to continue without paging--
#53 0x00007fffedcce7c9 in QTimerInfoList::activateTimers() () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#54 0x00007fffedccf051 in ?? () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#55 0x00007fffeea3ea1e in g_main_context_dispatch () from /home/andrew/tmp/calibre5/lib/libglib-2.0.so.0
#56 0x00007fffeea3eca8 in ?? () from /home/andrew/tmp/calibre5/lib/libglib-2.0.so.0
#57 0x00007fffeea3ed5c in g_main_context_iteration () from /home/andrew/tmp/calibre5/lib/libglib-2.0.so.0
#58 0x00007fffedccf41c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#59 0x00007fffedc6ebda in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#60 0x00007fffedc78357 in QCoreApplication::exec() () from /home/andrew/tmp/calibre5/lib/libQt5Core.so.5
#61 0x00007fffebcc09bb in ?? () from /home/andrew/tmp/calibre5/lib/calibre-extensions/PyQt5.QtWidgets.so
#62 0x00007ffff76e07d7 in PyCFunction_Call () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#63 0x00007ffff76a31d0 in _PyObject_MakeTpCall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#64 0x00007ffff773428a in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#65 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#66 0x00007ffff76d7183 in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#67 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#68 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#69 0x00007ffff76d7183 in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#70 0x00007ffff772f713 in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#71 0x00007ffff76d708a in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#72 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#73 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#74 0x00007ffff76d7183 in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#75 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#76 0x00007ffff7770a2f in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#77 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#78 0x00007ffff76d708a in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#79 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#80 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
--Type <RET> for more, q to quit, c to continue without paging--
#81 0x00007ffff76a07f3 in PyEval_EvalCodeEx () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#82 0x00007ffff76a081b in PyEval_EvalCode () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#83 0x00007ffff773eda4 in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#84 0x00007ffff76a6b97 in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#85 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#86 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#87 0x00007ffff76d7183 in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#88 0x00007ffff772e74d in _PyEval_EvalFrameDefault () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#89 0x00007ffff769faf3 in _PyEval_EvalCodeWithName () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#90 0x00007ffff76d7183 in _PyFunction_Vectorcall () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#91 0x00007ffff76beefd in PyVectorcall_Call () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#92 0x00007ffff77ada21 in ?? () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#93 0x00007ffff77ae6d6 in Py_RunMain () from /home/andrew/tmp/calibre5/lib/../lib/libpython3.8.so.1.0
#94 0x00007ffff7d6cfa8 in execute_python_entrypoint () from /home/andrew/tmp/calibre5/lib/libcalibre-launcher.so
#95 0x00000000004005cd in ?? ()
#96 0x00007ffff7b1ce6b in __libc_start_main () from /lib64/libc.so.6
#97 0x0000000000400609 in ?? ()
(gdb)

kovidgoyal · 12-29-2020, 12:16 AM

Looks like an issue in the Qt XCB backend. I suggest making sure the various xcb packages on your system are up to date.

andrew.46 · 12-29-2020, 03:55 AM

Quote:

Originally Posted by kovidgoyal

Looks like an issue in the Qt XCB backend. I suggest making sure the various xcb packages on your system are up to date.

Thanks again for looking at the issue. I have spent some time and effort with the problem and it is, as I was suspecting, a local configuration issue with my desktop environment. And obviously a non-Calibre issue which I have partly resolved now.

And thanks again for Calibre

andrew.46 · 12-29-2020, 10:13 PM

Just for the sake of completion I will put a more detailed explanation of the issue I uncovered on my system and the choice of fixes to rectify the issue.

I run Fluxbox, a very minimalist desktop, which as it turns out does not adequately set / show the DPI for my display. Other DEs available in a full installation of Slackware (Xfce and Plasma / KDE) do this automatically.

It looks like QT/Calibre automatically sets size of display, fonts etc by reading values relating to display, values which were not available on my Fluxbox setup. A bizarrely large value is then looked for which causes the error that I saw and the eventual segmentation fault of Calibre.

Solutions are all local and their are 2 choices:

Fix the display values on my system: the correct DPI can be set with xrandr easily enough, or entered into ~/.Xresource or any of several other choices.
Block the ability of QT/Calibre to auto-size at all by using QT_AUTO_SCREEN_SCALE_FACTOR=0 and perhaps allowing a fixed resize by using QT_SCALE_FACTOR=xxx.

I am happy now, I have learnt something new and I have the latest version of Calibre open even as I am typing

.

Thasaidon · 12-30-2020, 03:05 AM

Quote:

Originally Posted by andrew.46

[I]I am happy now, I have learnt something new and I have the latest version of Calibre open even as I am typing

.

Good for you.

I always feel a day when you HAVE NOT learned something new is a day wasted.

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12-28-2020, 03:56 AM	#1
andrew.46 Member Posts: 13 Karma: 2181720 Join Date: Jul 2018 Device: Kindle Oasis	QT Error with Calibre 5.8.1 but not with Calibre 4.23.0 I am happily running Calibre 4.15 and I was looking at installing and running the latest version on 64bit Slackware Linux: 5.8.1. However when using the binary provided from the Calibre site for 5.8.1 I get the following segmentation fault: Code: andrew@ilium~/tmp/calibre5$ ./calibre qt.qpa.xcb: xcb_shm_create_segment() can't be called for size 17178820624, maximumallowed size is 4294967295 Segmentation fault andrew@ilium~/tmp/calibre5$ For curiosity I also downloaded the binary from the Calibre web site for the last of the 4.x series: 4.23.0 and this ran without error. Curious... My suspicion is that is perhaps a local system error rather than a Calibre error (and I have posted on the Slackware Forums as well to cover this possibility) but I am posting here in case any wise Calibre users can give a steer.

12-28-2020, 06:58 AM	#2
kovidgoyal creator of calibre Posts: 45,320 Karma: 27111242 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Get a backtrace for the segfault, that might be more illuminating.

12-29-2020, 12:16 AM	#4
kovidgoyal creator of calibre Posts: 45,320 Karma: 27111242 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Looks like an issue in the Qt XCB backend. I suggest making sure the various xcb packages on your system are up to date.

12-29-2020, 10:13 PM	#6
andrew.46 Member Posts: 13 Karma: 2181720 Join Date: Jul 2018 Device: Kindle Oasis	Just for the sake of completion I will put a more detailed explanation of the issue I uncovered on my system and the choice of fixes to rectify the issue. I run Fluxbox, a very minimalist desktop, which as it turns out does not adequately set / show the DPI for my display. Other DEs available in a full installation of Slackware (Xfce and Plasma / KDE) do this automatically. It looks like QT/Calibre automatically sets size of display, fonts etc by reading values relating to display, values which were not available on my Fluxbox setup. A bizarrely large value is then looked for which causes the error that I saw and the eventual segmentation fault of Calibre. Solutions are all local and their are 2 choices: Fix the display values on my system: the correct DPI can be set with xrandr easily enough, or entered into ~/.Xresource or any of several other choices. Block the ability of QT/Calibre to auto-size at all by using QT_AUTO_SCREEN_SCALE_FACTOR=0 and perhaps allowing a fixed resize by using QT_SCALE_FACTOR=xxx. I am happy now, I have learnt something new and I have the latest version of Calibre open even as I am typing .

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