I'd like to announce the first release of a new tool called hackage-proxy. The purpose is to provide a local proxy for a Hackage server, which somehow modifies files in transport. The motivating case for this was getting more meaningful error output from Stackage when compiling against GHC HEAD. When compiling against actual Hackage, cabal will simply refuse to try to build packages which have upper version bounds such as "base < 4.7". This introduces a big dilemma: * Package authors do not want to bump the version bounds on their packages until they've tested against that version. * It's very difficult to do meaningful tests of GHC until packages on Hackage have been updated. Hopefully this package can help resolve the dilemma. Instead of requiring authors to upload new versions of their packages in order to test them, this proxy will modify the cabal files it downloads and strip off the version bounds of specified packages. Then, you can test with a newer version of GHC and find actual compilation errors instead of version bound constraints. ## Example Usage 1. cabal install hackage-proxy 2. Run hackage-proxy. By default, it will use the official Hackage server as the source, drop bounds on the packages base, process, directory, template-haskell, and Cabal, and serve from port 4200. All of this can be modified via command-line options. 3. Edit your ~/.cabal/config file. Comment out the hackage.haskell.orglines, and add in something like the following: remote-repo: hackage-proxy:http://localhost:4200 4. cabal update 5. cabal install your-package-list-here I think this can be a very valuable tool for anyone wanting to test out newer versions of GHC. In addition, as part of my normal Stackage work, I'm now collecting fairly detailed error logs of a number of packages. If this would be useful for the GHC team or anyone else, let me know and I can try and provide the logs somehow.