Bug#974538: libkscreenlocker5: kwin cannot start due to missing libkscreenunlocker5 symbols

[Ben Wagner <bungeman@chromium.org>]

$ which kwin
/usr/bin/kwin

$ dpkg -S usr/bin/kwin
kwin-x11: /usr/bin/kwin
kwin-x11: /usr/bin/kwin_x11

$ ls -l /usr/bin/kwin
/usr/bin/kwin -> kwin_x11

$ dpkg --list kwin-x11
ii kwin-11 4:5.17.5-4 amd64 KDE window manager, X11 version

$ kwin --version
kwin: symbol lookup error: /lib/x86_64-linux-gnu/libkwin.so.5:
undefined symbol:
_ZN12ScreenLocker7KSldApp30greeterClientConnectionChangedEv

$ sudo apt clean

$ sudo apt install --reinstall kwin-x11 libkscreenlocker5
... finishes with no errors ...

$ kwin --version
kwin: symbol lookup error: /lib/x86_64-linux-gnu/libkwin.so.5:
undefined symbol:
_ZN12ScreenLocker7KSldApp30greeterClientConnectionChangedEv

$ objdump -T /lib/x86_64-linux-gnu/libkwin.so.5 | grep
greeterClientConnectionChanged
0 DF *UND* 0 _ZN12ScreenLocker7KSldApp30greeterClientConnectionChangedEv

$ dpkg -S lib/x86_64-linux-gnu/libkwin.so.5
kwin-common: /lib/x86_64-linux-gnu/libkwin.so.5.17.5
kwin-common: /lib/x86_64-linux-gnu/libkwin.so.5

$ dpkg --list kwin-common
ii kwin-common 4:5.17.5-4 amd64 KDE window manager, common files

$ sudo apt install --reinstall kwin-x11 libkscreenlocker5 kwin-common
... finishes with no errors ...

$ kwin --version
kwin: symbol lookup error: /lib/x86_64-linux-gnu/libkwin.so.5:
undefined symbol:
_ZN12ScreenLocker7KSldApp30greeterClientConnectionChangedEv