Building on Windows

I'm trying to test a patch I wrote for Windows builds[1]. I'm following the preparation guide[2], but my configure step fails[3] with config.log contents[4]. Note that I'm building on the ghc-7.10 branch, not master. Is it possible that this would contribute to the unrecognized --enable-tarballs-autodownload option, and/or the inability to compile C files? [1] https://phabricator.haskell.org/D1158, handles long linker command line arguments [2] https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Windows [3] http://lpaste.net/139330 [4] http://lpaste.net/139331