It is not possible to have spaces in the path of the target directory.
The error message is:
Undefined subroutine &main::error called at /usr/local/bin/stow line 568.
If lines 567-569 are commented out then stow runs but fails to change directory into the path prefix of the directory with a space in its name.
This occurs notwithstanding the spaces being escaped or the full directory path being quoted.
On OS X spaces are unfortunately in some of the system paths e.g. `~/Library/Application Support` so I can't use it to manage files below these directories.
John