Make Happy Explicitly Depend on Perl

[Duncan Coutts]

On Sun, 2010-01-10 at 11:07 +0000, Dominic Steinitz wrote:
> Probably no-one has ever built happy on a machine without perl so this
> has never been noticed. I think it's more polite to fail at the
> configure stage rather than the build stage. In the cabal file I think
> we should have

I've been meaning for some time to exorcise perl from the happy build.
The little bit of substituting could fairly easily be done in Haskell
code in the Setup.hs rather than calling perl. As Neil says, this would
also help Windows users.

Perhaps someone else has the time to give that a go.

In the mean time "build-tools: perl" is of course correct.

Duncan