There is an ongoing outage on the primary CPAN mirror. It is possible to work around the issue by using MetaCPAN as a mirror.
To install Devel::SlowBless, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Devel::SlowBless
CPAN shell
perl -MCPAN -e shell install Devel::SlowBless
For more information on module installation, please visit the detailed CPAN module installation guide.