cpan[2]> o conf /make|build|install/
$CPAN::Config options from /home/parv/.cpan/CPAN/MyConfig.pm:

    build_cache        [100]
    build_dir          [/home/parv/.cpan/build]
    build_dir_reuse    [0]
    build_requires_install_policy [yes]
    cleanup_after_install undef
    make               [/usr/bin/make]
    make_arg           []
    make_install_arg   [PREFIX=/home/parv/test-perl5]
    make_install_make_command [/usr/bin/make]
    makepl_arg         [PREFIX=/home/parv/test-perl5]
    mbuild_arg         [--install_base /home/parv/test-perl5]
    mbuild_install_arg []
    mbuild_install_build_command [./Build]
    mbuildpl_arg       []
    prefer_installer   [MB]