compile failed with 'HAVE_IPv6' opened under Mingw32/Win7

Dear everyone:
     I met the following error when add 'EXTRA_DEFINES = -DWIN32
-DHAVE_IPv6' to Makefile.
F:\Python\LibEvent\Proxy\polipo>make
cc  -Os -g -Wall -fno-strict-aliasing -DLOCAL_ROOT=\"./www/\"
-DDISK_CACHE_ROOT=\"./polipo/\"  -DWIN32 -DHAVE_IPv6   -c -o util.o
util.c
cc  -Os -g -Wall -fno-strict-aliasing -DLOCAL_ROOT=\"./www/\"
-DDISK_CACHE_ROOT=\"./polipo/\"  -DWIN32 -DHAVE_IPv6   -c -o event.o
event.c
cc  -Os -g -Wall -fno-strict-aliasing -DLOCAL_ROOT=\"./www/\"
-DDISK_CACHE_ROOT=\"./polipo/\"  -DWIN32 -DHAVE_IPv6   -c -o io.o io.c
io.c: In function 'do_scheduled_connect':
io.c:517:25: error: storage size of 'servaddr6' isn't known
io.c:582:58: error: invalid application of 'sizeof' to incomplete type 'struct i
n6_addr'
io.c:517:25: warning: unused variable 'servaddr6' [-Wunused-variable]
io.c: In function 'do_scheduled_accept':
io.c:674:10: warning: pointer targets in passing argument 3 of 'win32_accept' di
ffer in signedness [-Wpointer-sign]
mingw.h:109:9: note: expected 'socklen_t *' but argument is of type 'unsigned in
t *'
io.c: In function 'create_listener':
io.c:694:25: error: storage size of 'addr6' isn't known
io.c:737:9: warning: implicit declaration of function 'inet_pton' [-Wimplicit-fu
nction-declaration]
io.c:694:25: warning: unused variable 'addr6' [-Wunused-variable]
io.c: In function 'parseNetAddress':
io.c:955:21: error: storage size of 'ina6' isn't known
io.c:955:21: warning: unused variable 'ina6' [-Wunused-variable]
io.c: In function 'netAddressMatch':
io.c:1103:25: error: storage size of 'sain6' isn't known
io.c:1107:10: warning: pointer targets in passing argument 3 of 'win32_getpeerna
me' differ in signedness [-Wpointer-sign]
mingw.h:111:9: note: expected 'socklen_t *' but argument is of type 'unsigned in
t *'
io.c:1118:14: warning: pointer targets in passing argument 3 of 'win32_getpeerna
me' differ in signedness [-Wpointer-sign]
mingw.h:111:9: note: expected 'socklen_t *' but argument is of type 'unsigned in
t *'
io.c:1103:25: warning: unused variable 'sain6' [-Wunused-variable]
make: *** [io.o] Error 1

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