I got this today after trying to install JSON::XS, which has Types::Serialiser as a prerequisite.
cpan> install Types::Serialiser Running install for module 'Types::Serialiser' The module Types::Serialiser isn't available on CPAN. Either the module has not yet been uploaded to CPAN, or it is temporary unavailable. Please contact the author to find out more about the status. Try 'i Types::Serialiser'. cpan> i Types::Serialiser Module id = Types::Serialiser CPAN_VERSION undef CPAN_FILE N/A INST_FILE (not installed) - philgoetz at gmail