pltcl_*mod commands are broken on Solaris 10

Commands pltcl_listmod, pltcl_delmod, pltcl_loadmod does not work on Solaris 10, 
because there is not present tclsh. Unfortunately build process substitute  path 
to shell with empty string which invokes infinite loop.

See diff between S10 and Nevada:

bash-3.00# head /usr/postgres/8.3/bin/pltcl_listmod
#! /bin/sh
# $PostgreSQL: pgsql/src/pl/tcl/modules/pltcl_listmod.in,v 1.3 2006/03/11 
04:38:40 momjian Exp $
#
# Start tclsh \
exec  "$0" "$@"

---------------------------------------------------------

bash-3.2$ head pltcl_listmod
#! /bin/sh
# $PostgreSQL: pgsql/src/pl/tcl/modules/pltcl_listmod.in,v 1.3 2006/03/11 
04:38:40 momjian Exp $
#
# Start tclsh \
exec /usr/bin/tclsh "$0" "$@"


By main opinion main problem is in build process which does not fail and also 
dependency on tclsh is hidden by exec command.
    Any idea how to fix it?                Zdenek


-- 
Zdenek Kotala              Sun Microsystems
Prague, Czech Republic     http://sun.com/postgresql