Troubleshooting CPAN.pm

I was having problem with Perl modules. When I decided to force install Bundle::CPAN again, I get this error message

CPAN.pm needs either the external programs tar, gzip and bzip2 installed. Can’t continue.

The problem was that somehow I screwed up CPAN.pm configuration. Don't know how I did this but my best guess is I forgot to use sudo when I tried to install Perl modules.

Anyhow, the solution was very easy:

shell> sudo perl -MCPAN -eshell
cpan> o conf tar /bin/tar
cpan> o conf bzip2 /bin/bzip2
cpan> o conf gzip /bin/gzip
cpan> o conf commit