Cabal Bug / Feature and Improvement
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" 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. Dominic. In Config.hs: loadConfig :: Verbosity -> GlobalFlags {-Flag FilePath-} -> Flag Bool -> IO SavedConfig loadConfig verbosity globalFlags {-configFileFlag-} userInstallFlag = addBaseConf $ do configFile <- maybe defaultConfigFile return (flagToMaybe (globalConfigFile globalFlags){-configFileFlag-}) minp <- readConfigFile mempty configFile case minp of Nothing -> do notice verbosity $ "Config file " ++ configFile ++ " not found." notice verbosity $ "Writing default configuration to " ++ configFile commentConf <- commentSavedConfig initialConf <- initialSavedConfig writeConfigFile configFile commentConf (initialConf `mappend` (mempty {savedGlobalFlags = globalFlags})) return initialConf The other cases of loadConfig are unchanged. In Main.hs global replace: loadConfig verbosity (globalConfigFile globalFlags) by loadConfig verbosity globalFlags
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. 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. Duncan
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@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.
On Fri, 2008-12-26 at 22:03 +0000, Dominic Steinitz wrote:
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@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".
So what you want is for the initial package config file to contain the settings you specify on the command line? It seems to me that's likely to lead to confusion because those settings would not be saved if the config file already existed. If we want a way of creating a config file from command line settings (and the use case for that is not at all clear to me) then I think it should be explicit. What seems more useful is to avoid creating any config file at all.
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.
I think it's in Main. We combine (using mappend) flags from three sources, the defaults, any config file and the command line.
Do you concur with my view on what should be put in the config-file?
I'm not sure that I do. I think I'd like to see the bigger picture of what you're really trying to achieve.
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
Honestly, I'm not quite sure what you're trying to do exactly. Perhaps seeing the whole patch would help or if you can explain the use case. Duncan
Duncan Coutts
I'm not sure that I do. I think I'd like to see the bigger picture of what you're really trying to achieve.
Honestly, I'm not quite sure what you're trying to do exactly. Perhaps seeing the whole patch would help or if you can explain the use case.
Here's my use case. I've expressed in the form of requirements and how I think they could be solved using ghc and cabal. We have a small team of developers and a much larger team of users who use a very restricted subset of Haskell. We have a version control system. We want everyone to use exactly the same community packages. Currently, we keep these packages under version control and manually modify ghc's package.conf (also under version control). The reason we do this is that the developers and users are able to check out sources to an arbitrary location on their local disk and we want the users to be able to build and run our code without manual configuration or separate installation of anything. Furthermore, each developer and user could have several "workspaces" (checked out versions of the sources at different locations on their local disk) on the go at the same time. We modify ghc's package.conf to use $topdir and relative paths - see http://www.nabble.com/Re%3A-haddock-not-finding-base- lib-docs----%24topdir---p7699303.html - so that package.conf is in sync with the place where the developer / user has checked out their sources (without package.conf needing to be modified on a per user and per workspace basis). The requirement for everyone to use the exactly the same community packages is partly driven by audit requirements. Furthermore, because we are behind a proxy, currently we would have to get every user to modify their registry if we wanted them to install community packages. We'd rather not do that especially as these settings can get over-written e.g. when Internet Explorer gets patched. We'd like to move away from manually modifying ghc's package.conf and to doing things the community way by using cabal more. Here's what I think would work. 1. A developer realises that package A is required. He cabal fetches to a remote-repo-cache which is under version control. This will also fetch any dependencies. 2. He installs package A using the remote-repo-cache and specifying --package- db. Note that the package-db is "[]" in the version control system and only every gets updated in the checked out source. It never gets checked back in. The cabal install of package A updates the package-db. 3. He uses e.g. ghci with -package-conf, -no-user-package-conf and -package A. 4. He checks in the remote-repo-cache. 4. Now another developer wishes to work on the code. 5. He checks out the sources from version control and cabal installs all the packages in the remote-repo-cache specifying --package-db. We'd probably do this in our build system by automatically building any package that has appeared in the repo-cache since the last update. He now has all the packages in the remote-repo-cache and his package.db has been updated to reflect this even though the file itself is not ever checked into the version control system. We'd certainly want this to happen behind the scenes for our users who will not add packages but who will certainly use them (even if they don't realise they are). Dominic.
participants (2)
-
Dominic Steinitz -
Duncan Coutts