idlwave-library-path

idlwave-library-path is a variable defined in `idlwave.el'.
Its value is

nil

Documentation:
Library path for Windows and MacOS (OS9). Not needed under UNIX.
When selecting the directories to scan for IDL user catalog routine
info, IDLWAVE can, under UNIX, query the shell for the exact search
path (the value of !PATH). However, under Windows and MacOS
(pre-OSX), the IDLWAVE shell does not work. In this case, this
variable can be set to specify the paths where IDLWAVE can find PRO
files. The shell will only be asked for a list of paths when this
variable is nil. The value is a list of directories. A directory
preceded by a `+' will be searched recursively. If you set this
variable on a UNIX system, the shell will not be queried. See also
`idlwave-system-directory'.

You can customize this variable.