Finally, I can agree there may not be a bug involved -- if the behaviour I find is intentional.

1.PERL5LIB loads as empty for the cron-user and so misses out on install configurations that other user's enjoy, despite having been assigned an ordinary environment in the calling shell-script through loading a dot-command.

2.eval puts the name of an unsuccessfully loaded module into %INC and, even when deleted, and a known-fix applied to PERL5LIB, the eval rerun still FAILS. But, ignoring the FAIL return from eval, the module can actually be successfully loaded and run.

3.Unfortunately, getting a fixed-cron to build is not as easy as all that. It appears to be very distro specific, and only available as an RPM, the latest for my distro being the one I have. I am still looking. CGI::Carp did at least help to trap meta-errors previously going awol.

4.My install of 5.8.7 has no problems except with cron. It correctly detected an architecture of i686 and installed accordingly, configured to correctly find user-pre-installed modules under Redhat's 'vendor-perl'/5.8.0/'i386' install, using PERL5LIB paths. My guess is that the empty PERL5LIB awarded to cron is to blame together with module search-logic that restricts itself to a single arch (i686 OR i386) only??