sub switch_to {
    my ( $self, $dist, $alias ) = @_;

    die "Cannot use for alias something that starts with 'perl-'\n"
      if $alias && $alias =~ /^perl-/;

    die "${dist} is not installed\n" unless -d joinpath($self->root, "perls", $dist);

    if ($self->env("PERLBREW_BASHRC_VERSION")) {
        local $ENV{PERLBREW_PERL} = $dist;
        my $HOME = $self->env('HOME');
        my $pb_home = $self->env("PERLBREW_HOME") || $PERLBREW_HOME;

        mkpath($pb_home);
        system("$0 env $dist > " . joinpath($pb_home, "init"));

        print "Switched to $dist.\n\n";
    }
    else {
        $self->launch_sub_shell($dist);
    }
}