> I suggest you first try to do make cleanand rebuild.
Your suggestion was right : it works now, I have gp 2.5.1. AND readline 6.2. enabled in it.
Many thanks !
Before I mistankingly tried to repeat the make process several times without thinking of cleaning.
I still have trouble compiling some tex files in the documentation, but it is a now a purely tex-ish issue
and I'll ask on the appropriate mailing list about it.