> In that case, May I edit configure script to generate the HAVE_* defines?
> I'd like to add a statement to check the si_band to configure.ac.

Does Cygwin use configure? If yes, go for configure.

You can copy/paste my recent change for dirent.d_type field.

> I see.  I use the mercurial repository from next time.

Are you using git or hg? If you use hg, just change the config to not use
git format. If you use git, don't worry, I can review without the review
button.