cabal install franchise now works

[Duncan Coutts]

As of franchise-0.0.2 and cabal-install-0.5.10 it works to:

$ cabal install franchise


Previously the difficulty was in compiling the Setup.hs script that
franchise uses. Of course it's Setup.hs script imports other modules
from the local package. This is basically the same as how the Cabal
library is bootstrapped. Previously cabal-install was not telling ghc to
look in the right place to pick up other local modules.

So franchise is the first build system (apart from Cabal itself) to
implement the Cabal package spec. Which is nice.

The main ongoing difficulty will be that cabal-install and other
packaging systems, rpm, etc assume rather more than the original minimal
command line interface that the Cabal spec described.

Currently for "build-type: Custom" cabal-install assumes a number of
command line flags that are provided by the Cabal library implementation
and are not specified in the original spec.

That's something we may want to look at if we foresee multiple
implementations coming into common use.

Duncan