Thanks, I can confirm that the patch fixes the build, and all tests pass.
https://github.com/msys2/MSYS2-packages/blob/f9b85b46d0970f1698e8b147fce98ab0062c4df0/iperf/PKGBUILD#L21-L25
But: /* Define to 1 if you have the declaration of 'SO_TIMESTAMP', and to 0 if you don't. */ #define HAVE_DECL_SO_TIMESTAMP 0 which guards the declaration
But: /* Define to 1 if you have the declaration of 'SO_TIMESTAMP', and to 0 if you don't. */ #define HAVE_DECL_SO_TIMESTAMP 0
/* Define to 1 if you have the declaration of 'MSG_CTRUNC', and to 0 if you don't. */ #define HAVE_DECL_MSG_CTRUNC 1
2.2.0 fails to build: error: ‘ctrunc_warn_enable’ was not declared in this scope
This has been fixed in 5a4f14f69909ff8 I think
Mingw, gobject-introspection, missing glib2 headers