(compile -s -O2 mailbox-threads.scm -j mailbox-threads)
(compile -s -O2 mailbox-threads.import.scm)
(compile -c -O2 mailbox-threads.scm -unit mailbox-threads)

(install-extension
   'mailbox-threads
   '("mailbox-threads.o" "mailbox-threads.so"
     "mailbox-threads.import.so")
   '((version 1.4)
     (static "mailbox-threads.o")
     (documentation "mailbox-threads.html")))