posting another solution, or really, workaround / hack.

my situation involves corporate vpn. I have cygwin on my wxp pc. i CAN disconnect from the vpn everytime i want to do cpan, but i'd rather not. I can dl modules via search.cpan.org manually, and i just want to use CPAN to make & install them.

especially today, because yesterday i was in the middle of installing things when emacs-on-cygwin hung. I believe all modules finished installing, but i just want to use perl -MCPAN -e shell to check whether they were really installed or not, and to pick up from where they left off if not finished.

I also think that the CPAN automatic dependency checking is very convenient.

so i found a work around

perl -MCPAN -e shell
cpan> o conf index_expire 1000
cpan> make Some::Module
[download]

this sets the index_expire config variable to 1000 days. that's abt 3 years. it was only temporarily set for this run, which is nice.