GLFW with Cygwin - undefined references to GL

GLFW with Cygwin - undefined references to GL

I'm attempting to compile this tutorial
http://www.opengl-tutorial.org/beginners-tutorials/tutorial-1-opening-a-window/
with Cygwin. I'm getting the following errors:
$ g++ main.cpp -o main -lm -lgl -lglut -lglew -lglfw
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(window.o):window.c:(.text+0
x927): undefined reference to `_imp__glClear@4'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x26d): undefined reference to `_imp__wglMakeCurrent@8'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x27e): undefined reference to `_imp__wglDeleteContext@4'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x11a0): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x11c8): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x11f0): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1394): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x150f): undefined reference to `_imp__wglMakeCurrent@8'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1520): undefined reference to `_imp__wglGetProcAddress@4'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1661): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1696): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x16d1): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1712): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x17a5): undefined reference to `_imp__wglCreateContext@4'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1800): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1984): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x19b1): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1a71): undefined reference to `_imp___iob'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1cb1): undefined reference to `_imp__glGetIntegerv@8'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1ccc): undefined reference to `_imp__glGetFloatv@8'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1cd2): undefined reference to `_imp__glClearColor@16'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o):win32_windo
w.c:(.text+0x1d06): undefined reference to `_imp__glClear@4'
/usr/lib/gcc/i686-pc-cygwin/4.7.3/../../../../i686-pc-cygwin/bin/ld:
/usr/lib/gc
c/i686-pc-cygwin/4.7.3/../../../libglfw.a(win32_window.o): bad reloc
address 0x0
in section `.rdata'
collect2: error: ld returned 1 exit status
What may be causing these errors?