Windows installer - beta release

[Mikhail Glushenkov]

Hi Duncan,

> I think as far as possible we should be consistent with the existing ghc
> installer.

Yes, that was my intent.

> And I think the existing ghc installer puts this directory (or perhaps
> it's the /bin subdir) on the %PATH%.

Yes, we also do that. 

> > I decided to use $SYSTEMDRIVE\ghc for GHC just in case it has
> > objections to being run from a directory with spaces in it.
> 
> There is no problem with it being run from a directory with spaces. The
> only problem is building it with a --prefix set to a dir with spaces, or
> if the source tarball is in a dir with spaces. The existing installers
> for ghc install to program files/ghc I think. You might like to double
> check that.

No, it uses $SYSTEMDRIVE\ghc\

See

http://github.com/ghc-hq/ghc/blob/de6aeb63286d5bd79a7c1f5003e970d25f883a31/distrib/ghc.iss

In general, I tried to mimic the existing GHC installer's
behaviour.

> Does the new installer let you specify a different location during
> installation? Is that enough or do you also need to distinguish the case
> of writing to the registry HKLM vs HKCU? What does the existing ghc
> installer do?

The existing GHC installer modifies HKCR - I'm not sure if
ordinary users are allowed to do this. I haven't also looked into
where Inno Setup writes its settings.

The new installer by default installs for all users. To install
only for the current user, we'd need to be careful to write only
to HKCU. Also, ~/.cabal/config would have to be modified so that
cabal-install doesn't try to write to Program Files\Haskell.