BUG #5178: make check fails because of locale en_AU.US-ASCII

The following bug has been logged online:

Bug reference:      5178
Logged by:          Boh Yap
Email address:      bhyz00@gmail.com
PostgreSQL version: 8.4.1
Operating system:   Mac OSX 10.5.8
Description:        make check fails because of locale  en_AU.US-ASCII
Details:

installing from src,
after doing ./configure and make,
make check
failed, when trying to initdb,  with this message in log:

  could not determine encoding for locale "en_AU.US-ASCII": codeset is
"US-ASCII"

but "en_AU.US-ASCII" is in /usr/share/locale

my LANG, LC_CTYPE, LC_COLLATE all contain the above locale value.

did not proceed with install as I suspect initdb will fail.