Eclipse Mars and Arduino 1.6.5

The console window is quite "clean" :

23:26:07 **** Incremental Build of configuration Release for project qqq ****
make all

23:26:13 Build Finished (took 5s.781ms)

What confuses me are the numerous environment and path variables to be set all over the place. Right now the problems window lists :

Invalid project path: Duplicate path entries found (/qqq [Include path] isSystemInclude:true includePath:C:/Program Files (x86)/arduino-1.6.5-r5/hardware/tools/avr/avr/include), path: [/qqq]. qqq pathentry Path Entry Problem