Something is wrong with the libfltk1 libraries.
When using them for example with tigervnc-vncviewer, the cursor (mouse pointer)
is not changing according to the window wishes from the vncserver as expected.
Only an arrow is shown!
One would expect that this is a problem of tigervnc-viewer, but when I just
copy all /usr/lib/x86_64-linux-gnu/libfltk* from a Ubuntu 17.10 to my OpenSuSE
Tumbleweed, all works great again.

This problem also persists if I compile fltk-1.3.4-2 from the sources.
Also a self compiled version of tiger-vncviewer shows the problem, and also the
problem vanishes with the fltk-library from Ubuntu. 

The strange thing: the fltk/test/cursor application works well with the
Tumbleweed-FLTK and all different mouse cursors are show.

Any hint, what could be the problem?