Hi Aleix,

> The Makefile.am refers to FFI_CFLAGS and FFI_CFLAGS FFI_LIBS, but I
> don't see any reference to them and there's no PKG_CHECK_MODULES or
> anything that could define those in configure.ac or any m4 macro.

> Adding PKG_CHECK_MODULES line solved the issue:

>     PKG_CHECK_MODULES(FFI, libffi >= 3.3.0)

Wow, well spotted Aleix!

The thing is, the bug never ever triggered here, not even once (in
quite a few 'build checks', in between these changes and the two next
releases: I can't explain why, just that I am using gcc and, maybe, an
unexpected(unwilling) behavior ... i  would be nice to  find out, if
anyone has an idea ... please enlighten me :), thanks.

I just pushed your proposed fix to the devel branch.

Thanks Aleix,
David