createdb script bug in 7.3RC2?

Seems to be a bug in the bin/createdb script. I tried to use the script
as is and got the following error:

$ createlang plpgsql JC
ERROR: stat failed on file '$libdir/plpgsql': No such file or directory
createlang: language installation failed

But my PGLIB path is correct:

$ set | grep PG
PGDATA=/usr/local/pgsql/data
PGLIB=/usr/local/pgsql/lib

I editing bin/createdb, hard coding the value of PGLIB and createdb then
worked fine. The edits are given below.I don't know any shell scripting
or much about pg's internal so I have no idea why this problem occurs.

But I can see why createdb can't figure out by itself what the value of
PGLIB is.

The edits on bin/createlang:

189a190
> PGLIB=/usr/local/pgsql/lib

Hope this helps. And if it is not a bug but a problem with my
installation, configuration please let me know.

Jc