@codebrainz, @b4n: thanks for all your help with the build system. :1st_place_medal:
Finally, calling ```ldconfig /usr/local/lib``` on the command line before building geany-plugins did the job :sweat: (So, yes I am using Ubuntu).
I tried to do it automatically by adding it somewhere in the Makefiles but failed because I just do not know anything about the principles of autotools/automake. And I have to admit that I do not want to work into it because I dislike make to much and the autotools do not seem to make the job simpler.
Although I think that it is a little shame that the libdirs are not the same amongst the different linux versions.
Anyway, that's not our fault.
Now that it works, how do we proceed now? I would like to place a fresh PR which only includes the changes for the common lib (leave workbench unchanged in that PR). Once that is merged I would place a PR for workbench which replaces the code.