* guix/profiles.scm (manual-database)[build]: Use 'with-extensions'.
Remove 'add-to-load-path' call.
* guix/man-db.scm: Use (gdbm) the normal way; remove 'module-autoload!'
call.
Fixes 'guix pull'.
Reported by ofosos on #guix.
* guix/man-db.scm: Use 'module-autoload!' instead of 'module-use!'.
so that (gdbm) is not loaded until we need it.
Fixes <https://bugs.gnu.org/29654>.
Reported by Ruud van Asseldonk <dev+guix@veniogames.com>.
This also speeds up database creation compared to "man-db
--create" (less than half the time, on a warm cache, for 19k pages.)
* guix/man-db.scm: New file.
* Makefile.am (MODULES_NOT_COMPILED): Add it.
* guix/profiles.scm (manual-database): Rewrite to use (guix man-db).
