+my @optionals = (
+ qw/Audio::FLAC::Header 0
+ Audio::Opusfile 0
+ MP3::Info 0
+ MP4::Info 0
+ Ogg::Vorbis::Header::PurePerl 0/,
+);
+
+sub is_installed {
+ my ($module) = @_;
+ eval "require $module"
+}
+
+my @extra_prereqs;
+
+unless (grep \&is_installed, @optionals) {
+ my $answer = '';
+ while (!$answer) {
+ my $yn = lc prompt 'None of the optional dependencies are installed. Install all of them? (default: y) [y/n]', 'y';
+ $answer = $yn if $yn eq 'y' || $yn eq 'n';
+ }
+ @extra_prereqs = @optionals if $answer eq 'y';
+}
+