The code looks at db(1) btree files stored in PKGFS_DEPSDIR to know
what dependencies are required for X package, and walks the dependency
chain every time that X package contains a deps .db file.
Every time a package is stowned, the pkg is registered into
PKGFS_DESTDIR/.pkgfs-registered-pkgs.db, and removed when it's unstowned.
--HG--
extra : convert_revision : b5222a890dd41b96dc72ee3e90bb72a282fe0841
