I did it by holding left mouse button, click right mouse button, let loose left mouse button and right moue button.
Somehow I have succeeded in making the bender slider a stand still on -1350 which is what I was looking for. I don't know how I did that. Until now the slider moved back to 0 every time I moved the slider and let go.
Controlling pitch value
Actually, I have a better fix, because the installation at /usr/local is not ideal,...
OK, it is a know problem (e.g. https://stackoverflow.com/questions/24983181/cpack-generates-rpms-with-files-entries-that-conflict-with-the-rpm-spec-how-to)...
I see. I'll try to find some time to take a closer look so that I can suggest a ...
[herald@xps13 cmake_build]$ rpm -qlp lensfun-0.3.2.0-Linux.rpm /usr/local /usr/local/bin...
lensfun rpm tries to create dierctories owned by the filesystem rpm