Build - scsynth on macOS doesn't appear to honour the ; separator for multiple ugen plugin paths

Instead fall back to a single plugin directory and copy extra plugins across during prebuild

Author: samaaron

app/gui/qt/mac-prebuild.sh

@@ -29,6 +29,8 @@ rm -rf ${SCRIPT_DIR}/../../server/native/scsynth
 cp -R ${SCRIPT_DIR}/../../../prebuilt/macos/x64/* ${SCRIPT_DIR}/../../server/native/
 cd ${SCRIPT_DIR}/../../server/native/
 ln -s supercollider/scsynth scsynth
+mv supercollider/extra-plugins/* supercollider/plugins/
+rm -rf supercollider/extra-plugins
 
 echo "Compiling native ruby extensions..."
 ruby "${SCRIPT_DIR}/../../server/ruby/bin/compile-extensions.rb"

app/server/ruby/lib/sonicpi/scsynthexternal.rb

@@ -364,7 +364,7 @@ def boot_server_osx
 
       local_scsynth_opts = {
         "-i" => num_inputs,
-        "-U" => "#{native_path}/supercollider/plugins/;#{native_path}/supercollider/extra-plugins"
+        "-U" => "#{native_path}/supercollider/plugins/"
       }
 
       scsynth_opts = @default_scsynth_opts.merge(local_scsynth_opts).merge(@user_scsynth_opts).to_a.flatten