Hello Marco, I have a branch pending to fix free-identifier=? in Guile. It will probably go in 2.0.2.
However, even with this patch, test-flatt-syntactic.sps still fails because of two things, one difficult and the other even more so: 1) Bug https://savannah.gnu.org/bugs/?31472 -- the introduced "the-parent-rtd" identifier gets resolved relative to the (synrec6) module rather than the module of the expanded form. This will be fixed at some point. 2) Guile does not hygienically introduce toplevel bindings. I would like to fix it, but it will not be fixed in 2.0.x, as it would break ABI. You can work around this one as Guile's own srfi-9 does, if you so wish, by generating a temporary yourself. Regards, Andy -- http://wingolog.org/
