@sandro @hfaust @sun Well that part of autoconf is designed broken, like pretty much all of autoconf.
I don't think I've had a year where it didn't have a serious bug, even just compilers getting 2 digits in their major version broke it. And so each time more and more autoreconf gets added to packages, typically coming with patches so autoreconf would actually work, or even patches to ./configure directly because it just wouldn't work.