bug#32514: mailutils Guile bindings are broken

[Ricardo Wurmus <rekado@elephly.net>]

There are at least three problems with the Guile bindings for mailutils:

1. the Guile source files are not compiled.

2. the Guile source files are installed to $out/share/guile/site/ and
are thus not found with “,use (mailutils mailutils)” in a Guile REPL.

3. the Guile session segfaults when loading the module:

--8<---------------cut here---------------start------------->8---
rekado in debbugs [env]: guile
GNU Guile 2.2.4
Copyright (C) 1995-2017 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> (add-to-load-path "/gnu/store/50lg0i5rqw1g7nf0ar2afgs788mgdjmq-mailutils-3.4/share/guile/site/")
scheme@(guile-user)> ,use (mailutils mailutils)
;;; note: auto-compilation is enabled, set GUILE_AUTO_COMPILE=0
;;;       or pass the --no-auto-compile argument to disable.
;;; compiling /gnu/store/50lg0i5rqw1g7nf0ar2afgs788mgdjmq-mailutils-3.4/share/guile/site/mailutils/mailutils.scm
;;; compiled /home/rekado/.cache/guile/ccache/2.2-LE-8-3.A/gnu/store/50lg0i5rqw1g7nf0ar2afgs788mgdjmq-mailutils-3.4/share/guile/site/mailutils/mailutils.scm.go
Segmentation fault
rekado in debbugs [env]:
--8<---------------cut here---------------end--------------->8---

Are the bindings not usable with Guile 2.2?

--
Ricardo