Klaus
extern HardwareSerial Serial; will not fix the issue as the code compiles. (it should be defined as I include WProgram.h. It is an eclipse indexer problem.
Pito
Please see the freshly released web pages with more documentation. on Arduino Eclipse IDE named Sloeber - Welcome! There is a faq that should answer your questions.
Best regards
Jantje
Eclipse tells me there are bugs in my code but it compiles ok.
Eclipse compiles you code in 2 ways. Once when you request a build (when you press on the hammer) and ones when you change code (save a file). The compiler is responsible for the build and the indexer is responsible for the continuous build.
The bugs (the red animals in the code) you see in the code can be found by any of the 2. The indexer behaves weird and sometimes doesn't find declarations that it knows. In that case you have the bug without a bug (in other words the code compiles ok).
Setting the option windows->preferences->C/C++->indexer->index unused headers seems to have fixed the issue on my system.