Anton Triola - 2023-04-14 
I did a full update of MSYS on 4/12/23.
Got a compilation error in minwindef.h.
I don't see why it's erroring-out...

Error from minwindef.h:
--------------------------------------------
windres --include-dir=../include -DDEBUGBUILD=0 -O coff -F pe-x86-64 -i libcurl.rc -o libcurl.res
In file included from C:/msys64/mingw64/include/windef.h:9,
             from C:/msys64/mingw64/include/windows.h:69,
             from C:/msys64/mingw64/include/winsock2.h:23,
             from ../include/curl/system.h:408,
             from ../include/curl/curl.h:37,
             from curl_setup.h:161,
             from version.c:25:
C:/msys64/mingw64/include/minwindef.h:6:10: fatal error: ./specstrings.h: Invalid argument
    6 | #include <specstrings.h>
      |          ^~~~~~~~~~~~~~~
compilation terminated.
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First 16 lines of minwindef.h:

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 1 #ifndef _MINWINDEF_
 2 #define _MINWINDEF_
 3
 4 #include <_mingw.h>
 5 #include <winapifamily.h>
 6 #include <specstrings.h>
 7
 8 #if WINAPI_FAMILY_PARTITION (WINAPI_PARTITION_APP)
 9
10 #if !defined (STRICT) && !defined (NO_STRICT)
11 #define STRICT 1
12 #endif
13
14 #ifndef WIN32
15 #define WIN32
16 #endif
...
--------------------------------------------

First 22 lines of specstrings.h:

--------------------------------------------
 1 /**
 2 * This file has no copyright assigned and is placed in the Public Domain.
 3 * This file is part of the mingw-w64 runtime package.
 4 * No warranty is given; refer to the file DISCLAIMER.PD within this package.
 5 */
 6
 7 #ifndef SPECSTRINGS_H
 8 #define SPECSTRINGS_H
 9
10 #define __specstrings
11
12 #include <sal.h>
13
14 #ifdef __cplusplus
15 #ifndef __nothrow
16 #define __nothrow __declspec(nothrow)
17 #endif
extern "C" {