When running perldoc on certain Windows systems using Perl under Cygwin it is possible to get an error message Error in tempfile() using ./XXXXXXXXXX: Parent directory (./) is not writable This is more likely to happen if your system has been 'hardned' by a corporate IT department. The fix is as follows:
  1. Make sure $TMPDIR is defined and points to somewhere sensible (e.g. $TMP)
  2. Make sure you have read/write permissions (chmod 777 $TMPDIR)