Error when I building project of NIOS II IDE

Hi, I had this problem too, but in the SOPC Builder generation, not the IDE, and I found some tips on the web.

In my case, it was an incompatibility between cygwin and a Mac Afee feature (memory overflow protection).

Some might have the problem with others antivirus like Norman or Panda.

Try to deactivate your antivirus and test.

One more thing, be sure to have only one version of cygwin (Quartus ones) installed on your computer, if not, rename all cygwin1.dll.

Good luck.