(compile -s -O2 -d0 yelp.scm -j yelp)
(compile -c -O2 -d0 yelp.scm -unit yelp)
(compile -s -O2 -d0 yelp.import.scm)
(install-extension 
 'yelp
 '("yelp.so" "yelp.o" "yelp.import.so")
 '((version 1.0.3)
   (static "yelp.o")))