wish cabal-dev to travel back in time

[agocorona]

When compiling old developments, I wish cabal-dev to install and build dependencies that were available at a that time

motivation:

I´m installing now an old soft development. Since my dependencies were labeled with -any, neither I neither cabal know which library versions are the right ones. By taking into account a date parameter, cabal-dev can figure out which libraries were the latest and the right ones at that time.

[isturdy]

Taking a quick look at the cabal library, it does not seem that cabal tracks dates (they being inserted into the Hackage description on upload, while cabal only cares about the .cabal file. If this is true, this would require going back to Hackage to resolve dates or a somewhat major change to the way indexes are construced--does anyone know more about this?