Installer fails for me, what is it with env?

[Hugh Sasse Staff Elec Eng]

I'm running into problems with the installer for the Ruby vim files.

brains# ./vim-ruby-install.rb
/usr/bin/env: No such file or directory
brains# ls /usr/bin/env
/usr/bin/env
brains# ls -l !$
ls -l /usr/bin/env
-r-xr-xr-x   1 root     bin         5268 Apr  6  2002 /usr/bin/env
brains# head ./vim-ruby-install.rb
#!/usr/bin/env ruby

# vim-ruby-install: install the Vim config files for Ruby editing
#
#  * scope out the target directry and get user to confirm
#    * if no directory found, ask user
#    * allow user to force a search for a Windows gvim installation
#  * find source files from gem or from current directory
#  * copy to target directory, taking account of
#    * line endings (NL for Unix-ish; CRLF for Windows)
brains# echo $PATH
/bin:/sbin:/usr/bin:/etc:/usr/local/bin:/adabas/bin:/adabas/pgm:/usr/sbin:/usr/bin
brains# which ruby
/usr/local/bin/ruby
brains# ruby ./vim-ruby-install.rb

Possible Vim installation directories:
   1) /usr/local/share/vim/vim62

Please select one (or anything else to specify another directory): 1
./vim-ruby-install.rb:246:in `chdir': cannot convert nil into String (TypeError)
         from ./vim-ruby-install.rb:246:in `install'
         from ./vim-ruby-install.rb:370
brains# ls -l /usr/local/share/vim*
total 4
drwxr-xr-x  14 root     other       1024 Jul 19  2002 old_vim61
drwxr-xr-x  16 root     other       1024 Feb 27  2004 vim62
brains#

OK, I probably need to get Vim 6.3 "real soon now" but why is env
giving me this rubbish, and is the chdir thing a known problem?  My
ruby claims to be :

ruby 1.8.2 (2004-07-29) [sparc-solaris2.9]

         Thank you
         Hugh