KDevelop 5 SVN fails to find plugins after local installation

[Alexander Shaduri]

Hello,

I installed KDevPlatform and KDevelop 5 from SVN on OpenSUSE
Leap 42.1 which comes with KF5 (5.15). I chose to install it into
/opt/local/kdevelop. Added /opt/local/kdevelop/lib64 to ld library path.

With KDevelop 4 I used to add its installation path to KDEDIRS and
then run kbuildsycoca4. However, this no longer seems to work with KF5
and KDevelop starts without any plugins.

The documentation seems to be outdated:
https://techbase.kde.org/Projects/KDevelop4/HowToCompile

How do I make KDevelop see its plugins?

Thanks,
Alexander