Arch Linux

akopich

Member

Registered: 2019-09-27

Posts: 7

Mendeley Desktop is slow under LXDE

Dear community,

Mendeley Desktop seems to be extremely sluggish when it's being run under LXDE. The problem is non-existent under KDE. Other Qt applications work fine under both LXDE and KDE. Moreover, feels like Mendeley uses different themes under KDE and LXDE, while the look of other Qt applications is the same under LXDE and KDE.

I have found this thread regarding a similar issue. The suggested solution didn't work.

Any suggestions?

Mendeley Desktop 1.19.5-1 (AUR mendeleydesktop-bundled) and 1.19.4 (official web site), LXDE 0.99, Openbox 3.6.1-4, QT5 5.13.

Nickolas0

Member

Registered: 2019-02-16

Posts: 30

Re: Mendeley Desktop is slow under LXDE

You may try if installing Mendeley from flatpak works better: https://flathub.org/apps/details/com.el … leyDesktop

akopich

Member

Registered: 2019-09-27

Posts: 7

Re: Mendeley Desktop is slow under LXDE

Same issue with flatpak.

BTW. I tried to remove KDE. This lead to exactly the same issue with all the Qt apps. Installing the package breeze resolved it for all the Qt apps, but not for mendeley. And the best part. Mendeley works fine under xfce.

Nickolas0

Member

Registered: 2019-02-16

Posts: 30

Re: Mendeley Desktop is slow under LXDE

The reason is mendeley doesn't use qt from system but bundles it's own.

akopich

Member

Registered: 2019-09-27

Posts: 7

Re: Mendeley Desktop is slow under LXDE

But why does it work fine under KDE and XFCE then?

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 15,396

Re: Mendeley Desktop is slow under LXDE

xfce uses gtk2 & gtk3 , not Qt.
When running under KDE the qt libs bundled with meneleydesktop-bindled clash with the system libs ones used by KDE.
Under xfce system qt isn't active, so there's no conflict.

Have you tried https://aur.archlinux.org/packages/mendeleydesktop/ ?
Its PKGBUILD indicates that tries to build mendely desktop against system installed qt libraries.

Last edited by Lone_Wolf (2019-09-30 09:06:18)

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

akopich

Member

Registered: 2019-09-27

Posts: 7

Re: Mendeley Desktop is slow under LXDE

I still don't get how the obvious difference between KDE and XFCE leads to the same result (mendeley working fine).

It feels like the issue is related to breeze package, as its removal leads to exactly the same behavior of all the other Qt aps.

I've tried AUR/mendeley. It fails to launch.

[valerij@zihl Downloads]$ mendeleydesktop 
QFSFileEngine::open: No file name specified
/opt/mendeleydesktop/lib/mendeleydesktop/libexec/QtWebEngineProcess --type=zygote --webengine-schemes=qrc:sLV --lang=en-US: relocation error: /opt/mendeleydesktop/lib/mendeleydesktop/libexec/QtWebEngineProcess --type=zygote --webengine-schemes=qrc:sLV --lang=en-US: symbol _ZN7content20localtime_r_overrideEPKlP2tm version Qt_5 not defined in file libQt5WebEngineCore.so.5 with link time reference
/usr/bin/mendeleydesktop: line 4: 145922 Trace/breakpoint trap   (core dumped) /opt/mendeleydesktop/lib/mendeleydesktop/libexec/mendeleydesktop.x86_64 "$@"

Was it compiled against a different Qt version?

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 15,396

Re: Mendeley Desktop is slow under LXDE

That message suggests it is.
I looked at the PKGBUILD and realised it doesn't compile mendeley against system-installed qt , just changes where mendely looks for qt.

I think we'd better get back to the bundled version .

For clarity (please correct if i'm wrong )

mendeley under XFCE works as intended
mendeley performance under KDE is or was good ?
mendeley with LXDE is bad

How is performance of mendeley under a very simple WM like twm ?
Install twm, xorg-xclock , xterm if needed, use /etc/X11/xinit/xinitrc to start it.

Last edited by Lone_Wolf (2019-10-01 12:34:25)

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

akopich

Member

Registered: 2019-09-27

Posts: 7

Re: Mendeley Desktop is slow under LXDE

"exec twm" in .xinitrc leads to "could not resolve keysym". I hope, a detailed discussion of the issue is redundant, so I've replaced it with "exec xterm", which starts fine.

To sum it up.

If breeze package is installed:
Mendeley works fine under xterm, xfce, kde. Works slowly under lxde.
Other Qt apps work fine under xterm, xfce, kde AND lxde.

If breeze package is removed, Mendeley and other Qt apps are slow under xterm, xfce, kde, lxde, kde.