[arch-general] kmail and qt5-webengine latest : no mail content

[SET]

Hello,

Since today's update installing qt5-webengine-5.7.0-4-x86_64.pkg.tar.xz, no 
mail content can be viewed in kmail. Reverting to 5.7.0-3 restores normal 
functioning. A long list of errors is output in console :

...
#32 0x7fe45aa61df9 <unknown>
#33 0x7fe459eec2f4 QtWebEngine::processMain()
#34 0x0000004006d3 <unknown>
#35 0x7fe458e20291 __libc_start_main
#36 0x00000040072a <unknown>
...

Upstream or Arch related, I just want to signal it.