I wrote up some rust low-level bindings for guile [1]. The problem is that Guile liberally uses setjmp/longjmp, which breaks rust destructors. It might be possible to fix this by wrapping every call the way rlua does [2], but I'm not familiar enough with Guile to know.
1: https://github.com/ysimonson/guile-sys
2: https://github.com/amethyst/rlua/issues/21