Running "make -f Makefile CONF=Release" in /home/evil/Test make -f nbproject/Makefile-Release.mk SUBPROJECTS= .build-conf make[1]: Entering directory `/home/evil/Test' mkdir -p build/Release/GNU-Linux-x86 gcc -c -O2 -o build/Release/GNU-Linux-x86/Test.o Test.c mkdir -p dist/Release/GNU-Linux-x86 gcc -o dist/Release/GNU-Linux-x86/test build/Release/GNU-Linux-x86/Test.o build/Release/GNU-Linux-x86/Test.o: In function `main': Test.c:(.text+0x39): undefined reference to `pthread_attr_setstacksize' Test.c:(.text+0x58): undefined reference to `pthread_create' Test.c:(.text+0x6a): undefined reference to `pthread_join' collect2: ld returned 1 exit status make[1]: *** [dist/Release/GNU-Linux-x86/test] Error 1 make[1]: Leaving directory `/home/evil/Test' make: *** [.build-impl] Error 2 Build failed. Exit value 2.