Kjetil Matheussen <k.s.matheussen@gmail.com> schrieb am Sat Feb 28 2015 at 12:33:52:

Yes, libpds is based on pd-extended and apparently runs find in fc21. Needed this patch:
(or simply just replace wish8.5 with "wish8.6" in s_inter.c)

Thanks. This patch seem to only address the Tcl/Tk version. As I have wish8.5 installed that's not a problem anymore.
The problem is that either 
a) the pd version I can build can't create a osc~ object, or
b) pd won't even build
depending on which sources ( svn, git, tar.bz2 ) and build instructions I use. (Currently I'm stuck with a lua issue.)
In both cases I think that the build instructions I could find are incomplete or wrong and thus my result is broken.