Cabal Bug / Feature and Improvement

[Dominic Steinitz]

Duncan Coutts wrote:
> On Wed, 2008-12-24 at 13:19 +0000, Dominic Steinitz wrote:
>> Currently if I do not want to use the default locations for cabal then the 
>> following:
>>
>>> dist\build\cabal\cabal.exe --config-file=urghh --remote-repo-cache=foo 
>>                             --verbose=3 update
>>
>> will create urghh but will still (silently) put the repository cache at 
>>
>> repoLocalDir = "C:\\Documents and Settings\\steinitd\\Application 
>> Data\\cabal\\packages\\hackage.haskell.org"
> 
> Ah so when the config file does not exist the --remote-repo-cache flag
> is ignored and the default value from the newly created config file is
> used instead.
> 
>> I've made a few changes which will put the cache at "foo".  I don't have access 
>> to darcs at the moment so I've attached the changes. Let me know if a
>> darcs patch is worth doing.
> 
> Yes please though check that it's not already fixed. I made some changes
> in that code relatively recently.

Ok I've grabbed the latest version via darcs and you certainly have done
something in this area. On linux I now get "foo" created with what look
like the right things in it. However:

dom at lagrange:~/cabal-install> cat urghh
remote-repo: hackage.haskell.org:http://hackage.haskell.org/packages/archive
remote-repo-cache: /home/dom/.cabal/packages

which looks a bit suspicious to me as /home/dom/.cabal doesn't exist
(presumably it isn't created). With my patch, "urghh" has what I believe
is the correct remote-repo-cache of "foo".

I haven't had chance to see where you made your change but it doesn't
look to be in the same area as where I made my change. If I get time
tomorrow I'll have a look.

Do you concur with my view on what should be put in the config-file?

> 
> There are a couple other path settings that are still hard coded and
> should really be configurable. We should also have a way to operate
> without any config file at all for install scripts etc.
> 

I think but I haven't checked that my change would over-write any
hard-coded global flag. Is that the required behaviour? I think this
could allow you to operate without a config file if all you need is the
global flags. I suspect users will need other flags but I think a slight
modification to the one I suggested could handle that by using "mappend"
to override all the hard-coded settings. Something like this maybe:

> initialConf `mappend` (mempty {savedGlobalFlags = globalFlags}) 'mappend`
> otherFlagsWhichNeedOverWriting

Dominic.