[Agda] Install failure ghc-7.0.2 / cabal solved

[Christoph Herrmann]

Hi Bengt,

On 23 Mar 2011, at 21:06, Bengt Nordstrom wrote:

> Christoph, how much time did you spend on this?

a few hours, but some of that as a background task. And I
hope to reuse cabal for other ghc-related software as well.
Please note: the problem is the combination of cabal 
and ghc with its libraries; not Agda as such.

It would be nice if the ghc web pages would tell explicitly which
version of cabal works with which version of ghc. It is strange that
the "stable" version of cabal is actually the wrong one for
the current version of ghc.

> And how much time would it take to make a one click install system?

You are asking the wrong person, but I guess that it will be quite
difficult. The problem is that a high share of the software
is outsourced to libraries, emacs and ghc. E.g., what would the
one-click installer need to do if ghc is installed in the wrong version;
break other software by installing the required one over it?

The situation would be simpler if Agda would come with its own
editor and also not rely on ghc being installed.

> Yes, I know you have to make a new one click install system every time
> we have a major update. But how many potential users are put off by
> the current system?

No one who actually needs Agda, I hope. But I know some 
people who might try Agda and they are put off by using emacs and 
difficult ghc installations, e.g. using cabal. However, the situation is
much worse for graphical user interfaces and ghc; it is a serious
problem of ghc.

Best Regards
--
 Dr. Christoph Herrmann
 University of St Andrews, Scotland/UK
 phone: office: +44 1334 461629, home: +44 1334 478648 
 email: ch at cs.st-andrews.ac.uk,  c.herrmann at virgin.net
 URL:   http://www.cs.st-andrews.ac.uk/~ch
 
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