use actual feature names rather than crate names for conditional compilation
@@ -8,10 +8,10 @@ extern crate shell_words;
#[cfg(feature = "alsa-backend")]
extern crate alsa;
-#[cfg(feature = "portaudio-rs")]
+#[cfg(feature = "portaudio-backend")]
extern crate portaudio_rs;
-#[cfg(feature = "libpulse-sys")]
+#[cfg(feature = "pulseaudio-backend")]
extern crate libpulse_sys;
#[cfg(feature = "jackaudio-backend")]
