weekly locate.updatedb fails silently

[Jet Nul <jetnul_(_at_)_gmail_(_dot_)_com>]

When I execute /etc/weekly

  # cd /etc
  # sh weekly

it tells me

  Rebuilding locate database:

it reports no errors, and produces a large
/var/db/locate.database

  -r--r--r--   1 root  wheel  1857592 Feb  7 23:35 locate.database

However, this database misses a lot of files!

When I go

  # cd /usr/libexec
  # ./locate.updatedb

it produces a larger /var/db/locate.database

  -r--r--r--   1 root  wheel  2175863 Feb  7 23:38 locate.database

which seems to contain all the files (at least
those I tested).  Can anyone tell me why the
default weekly script would fail when a manual
run succeeds?

Also, note that when the weekly script runs
it degrades the database back to its incomplete
version.

-Jet