我收到此错误消息。我试图用 CYGWIN 做正确的事情，我做错了什么吗？你需要更多信息？
"/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf
make[1]: Entering directory `/cygdrive/c/Users/Liam/Documents/NetBeansProjects/playing with c'
cygwin warning:
MS-DOS style path detected: build/Debug/Cygwin_4.x-Windows/hello\.d
Preferred POSIX equivalent is: build/Debug/Cygwin_4.x-Windows/hello/.d
CYGWIN environment variable option "nodosfilewarning" turns off this warning.
Consult the user's guide for more details about POSIX paths:
http://cygwin.com/cygwin-ug-net/using.html#using-pathnames
"/usr/bin/make" -f nbproject/Makefile-Debug.mk dist/Debug/Cygwin_4.x-Windows/playing_with_c.exe
make[2]: Entering directory `/cygdrive/c/Users/Liam/Documents/NetBeansProjects/playing with c'
mkdir -p dist/Debug/Cygwin_4.x-Windows
gcc -o dist/Debug/Cygwin_4.x-Windows/playing_with_c build/Debug/Cygwin_4.x-Windows/hello\ world.o build/Debug/Cygwin_4.x-Windows/main.o
nbproject/Makefile-Debug.mk:63: recipe for target `dist/Debug/Cygwin_4.x-Windows/playing_with_c.exe' failed
make[2]: Leaving directory `/cygdrive/c/Users/Liam/Documents/NetBeansProjects/playing with c'
nbproject/Makefile-Debug.mk:60: recipe for target `.build-conf' failed
make[1]: Leaving directory `/cygdrive/c/Users/Liam/Documents/NetBeansProjects/playing with c'
nbproject/Makefile-impl.mk:39: recipe for target `.build-impl' failed
build/Debug/Cygwin_4.x-Windows/main.o: In function `main':
/cygdrive/c/Users/Liam/Documents/NetBeansProjects/playing with c/main.c:14: multiple definition of `_main'
build/Debug/Cygwin_4.x-Windows/hello world.o:/cygdrive/c/Users/Liam/Documents/NetBeansProjects/playing with c/hello world.c:3: first defined here
collect2: ld returned 1 exit status
make[2]: *** [dist/Debug/Cygwin_4.x-Windows/playing_with_c.exe] Error 1
make[1]: *** [.build-conf] Error 2
make: *** [.build-impl] Error 2
BUILD FAILED (exit value 2, total time: 3s)