Compilation failure on Windows 10 Msys2 mingw64

[bill-e-ghote]

Obviously, configure thinks I'm on a native *nix system and not Msys2 "mostly POSIX" environment.

gsocket-1.4.42 has been configured:

Host..............: x86_64-w64-mingw32
Prefix............: /mingw64
Compiler..........: gcc
Compiler flags....: -O2 -Wall -g -O2
Preprocessor flags: -I./../include -I/mingw64/include
Linker flags......: -L/mingw64/lib
Libraries.........: -lssl -lcrypto -ldl

Configuration complete. Now type: make all install

$ make all
make all-recursive
make[1]: Entering directory '/c/Users/user/source/repos/gsocket'
Making all in lib
make[2]: Entering directory '/c/Users/user/source/repos/gsocket/lib'
gcc -DHAVE_CONFIG_H -I. -I.. -I./../include -I/mingw64/include -O2 -Wall -g -O2 -MT gsocket-util.o -MD -MP -MF .deps/gsocket-util.Tpo -c -o gsocket-util.o gsocket-util.c
In file included from gsocket-util.c:2:
gs-common.h:11:10: fatal error: sys/socket.h: No such file or directory
11 | #include <sys/socket.h>
| ^~~~~~~~~~~~~~
compilation terminated.
make[2]: *** [Makefile:389: gsocket-util.o] Error 1
make[2]: Leaving directory '/c/user/source/repos/gsocket/lib'
make[1]: *** [Makefile:385: all-recursive] Error 1
make[1]: Leaving directory '/c/user/source/repos/gsocket'
make: *** [Makefile:326: all] Error 2