FATAL: failed to initialize TimeZone to "UNKNOWN"

Hi,

While trying to initdb using cvs tip, it dumps below error output:

...
creating configuration files ... ok
creating template1 database in pgd/base/1 ...
FATAL: failed to initialize TimeZone to "UNKNOWN"
child process exited with exit code 1
...

I edited some files but don't think they're related with this problem.
Edited files are like.c, oracle_compat.c and pg_mb2wchar function in
mbutils.c. (Actually, IIRC, pg_mb2wchar function is used nowhere in
the code.)

Attached a gdb output (tz_error.gdb) for initdb. Also, here's an
"strace -s 256" output for initdb:
http://www.students.itu.edu.tr/~yazicivo/tz_error.strace
(I'm not so experienced in debugging; if you'd need any further
information just let me know.)

I'd be so appreciated to hear any kind of help/idea/suggestion.

Regards.