I have the problem, when building by MS-VC6.
An error occurs in the 8.1.0 present source codes.

nmake -f win32.mak
..\..\port\getaddrinfo.c(244) : error C2065: 'WSA_NOT_ENOUGH_MEMORY'
..\..\port\getaddrinfo.c(342) : error C2065: 'WSATYPE_NOT_FOUND'

This is used by winsock2.h. However, Construction of a windows base is
winsock.h.
Then, Since MinGW has special environment, this is right. but, it is not
found in VC6.
Furthermore, in getaddrinfo.c, IPV6-API is used by
LoadLibraryA("ws2_32");
Referring to of dll the external memory generates this violation by VC6
specification.

I considered whether the whole should have been converted into winsock2.
However, Now, DLL of MinGW creation operates wonderfully as it is.
That's right, it has pliability by replacement of simple DLL.
Then, I propose the system using winsock(non IPV6) in construction of
VC6.

Hiroshi Saito