I Installed Debian Stretch, FPC 3.0.0, Lazarus 1.6 which works great.
Then I wanted a version of Lazarus trunk that also uses FPC trunk. Without touching the working FPC and Lazarus installation made from Synaptic.
So I used SVN to download a new copy of Lazarus sources and issued "make bigide". Obviously fpc 3.0.0 was used. Then I made a shortcut to startlazarus on the desktop and started the new Lazarus. The plan was to go to settings (as below) and specify FPC trunk and its sources. And then recompile Lazarus with the result that FPC trunk would be used. When I specified the trunk locations in file settings, there was a message that 3.0.0 was expected. I ignored, rescanned fpc source and recompiled. But afterwards, Lazarus -> Help -> About still said FPC 3.0.0 is used. How can that be, and how to switch to trunk from here?