Whilst working with the VMware Perl SDK this morning I came across this error:

Server version unavailable at '<a href="https://hostname/sdk/vimService.wsdl">https://hostname:443/sdk/vimService.wsdl</a>' at /usr/lib/perl5/5.8.8/VMware/VICommon.pm line 545.

Turns out it can’t verify the server’s SSL certificate.

export PERL_LWP_SSL_VERIFY_HOSTNAME=0 in your shell before using a command, and it then works correctly.