error: Unable to get pack file http://source.winehq.org/git/wine.git/objects/pack/pack-7c2ab792c6e1c8f603b7...
Is this on a Mac, by any chance? I had similar problems using MacPorts's git with a proxy server. I also had Linux running in a VM on that machine, and fetching from the Linux VM always succeeded. The odd thing is, fetching from Linux also fixed the MacPorts git fetch for me, at least until the next day's update.
If this isn't on a Mac, I don't know what to tell you. --Juan