pert:
The reason it was so much longer before is that the Ethernet2 library causes a bunch of compiler warnings. After the first compilation the Arduino IDE caches the compiled library and uses that compiled file for all future compilations unless the library is modified or you change to a different selection in the Tools > Board menu (in which case the library is re-compiled on the next compilation). The reason for this is to make subsequent compilations faster. Since the library wasn't re-compiled the second time, you don't get any of its warnings in the compilation output.
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thanks! now i can compile without errors.