sox: remove version, add linker error message

Formula/sox.rb

@@ -1,13 +1,22 @@
 require 'formula'
 
 class Sox <Formula
-  url 'http://sourceforge.net/projects/sox/files/sox/14.3.0/sox-14.3.0.tar.gz/download'
-  version '14.3.0'
+  url 'http://downloads.sourceforge.net/project/sox/sox/14.3.0/sox-14.3.0.tar.gz'
   homepage 'http://sox.sourceforge.net/'
   md5 '8e3509804e6227273ef84092e1a2fea7'
 
+  depends_on 'libvorbis' => :optional
+
   def install
-    system "./configure", "--prefix=#{prefix}", "--disable-debug", "--disable-dependency-tracking", "--disable-gomp"
+    configure_args = [
+      "--prefix=#{prefix}",
+      "--disable-debug",
+      "--disable-dependency-tracking",
+    ]
+    # Linking error 'symbol not found' on 10.6 64-bit '"_gomp_thread_attr", referenced from:'
+    configure_args << "--disable-gomp"
+
+    system "./configure", *configure_args
     system "make install"
   end
 end