crle and missing libusb.so.1 library

Today I have installed SpamAssassin from a tar.gz archive on Solaris 10 10/09.
Though everything looked fine I faced the problem with invocation of sa-update - SpamAssassin rules updater.

$ sa-update
ld.so.1: gpg: fatal: libusb.so.1: open failed: No such file or directory
Killed
ld.so.1: gpg: fatal: libusb.so.1: open failed: No such file or directory
Killed
error: GPG validation failed!
The update downloaded successfully, but the GPG signature verification
failed.
channel: GPG validation failed, channel failed
$ gpg
ld.so.1: gpg: fatal: libusb.so.1: open failed: No such file or directory
Killed

(gnupg has been installed from a package from sunfreeware.com, but it was not a problem)

Quick truss session:

# truss gpg
[...]
stat64("/usr/local/lib/libusb.so.1", 0x080473A0) Err#2 ENOENT
stat64("/usr/local/ssl/lib/libusb.so.1", 0x080473A0) Err#2 ENOENT
stat64("/usr/openwin/lib/libusb.so.1", 0x080473A0) Err#2 ENOENT
stat64("/usr/lib/libusb.so.1", 0x080473A0)      Err#2 ENOENT
stat64("/usr/X11R6/lib/libusb.so.1", 0x080473A0) Err#2 ENOENT
stat64("/usr/local/BerkeleyDB.4.7/lib/libusb.so.1", 0x080473A0) Err#2 ENOENT
stat64("/lib/libusb.so.1", 0x080473A0)          Err#2 ENOENT
stat64("/usr/lib/libusb.so.1", 0x080473A0)      Err#2 ENOENT
ld.so.1: gpg: fatal: libusb.so.1: open failed: No such file or directory
[...]

find lookup:

# find /usr -name libusb.so.1
/usr/sfw/lib/libusb.so.1

...and I had to change the default library path.
The tool - crle - runtime linking environment configurator, was taken as the only fair solution.
Do not want to reproduce the manual pages, so, below is the syntax I had used.
Checking the current options:

# crle

Configuration file [version 4]: /var/ld/ld.config  
  Default Library Path (ELF):   /lib:/usr/lib  (system default)
  Trusted Directories (ELF):    /usr/lib/secure:/opt/sun/comms/calendar/SUNWics5/cal/lib

Command line:
  crle -c /var/ld/ld.config -s /usr/lib/secure:/opt/sun/comms/calendar/SUNWics5/cal/lib

Complementation of default library path:

# crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/sfw/lib -s /usr/lib/secure:/opt/sun/comms/calendar/SUNWics5/cal/lib

[CHECK]
# crle
Configuration file [version 4]: /var/ld/ld.config  
  Default Library Path (ELF):   /lib:/usr/lib:/usr/sfw/lib
  Trusted Directories (ELF):    /usr/lib/secure:/opt/sun/comms/calendar/SUNWics5/cal/lib

Command line:
  crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/sfw/lib -s /usr/lib/secure:/opt/sun/comms/calendar/SUNWics5/cal/lib
# exit
$ gpg
gpg: WARNING: using insecure memory!
gpg: please see http://www.gnupg.org/faq.html for more information
gpg: directory `/export/home/sa/.gnupg' created
gpg: new configuration file `/export/home/sa/.gnupg/gpg.conf' created
gpg: WARNING: options in `/export/home/sa/.gnupg/gpg.conf' are not yet active during this run
gpg: keyring `/export/home/sa/.gnupg/secring.gpg' created
gpg: keyring `/export/home/sa/.gnupg/pubring.gpg' created
gpg: Go ahead and type your message ...
^C
gpg: signal 2 caught ... exiting
$ sa-update
gpg: WARNING: using insecure memory!
gpg: please see http://www.gnupg.org/faq.html for more information
$

Final notes
The syntax being used could be shortened to a form of:

# crle -u -l /usr/sfw/lib

where -u stands for existing configuration (file /var/ld/ld.config) update.
But be aware that by omitting the -u argument you turn your box into soldered fish tin, until you turn the other directories to the default path.

# crle -l /usr/sfw/lib
# init
ld.so.1: init: fatal: libpam.so.1: open failed: No such file or directory
Killed
# crle -u -l /lib -l /usr/lib -l /usr/sfw/lib
# init
Usage: init [0123456SsQqabc]
#