[Haskell-cafe] test driving cabal install... cabal install and normal install (runghc Setup) don't mix... two package.conf files...

[Spencer Janssen]

On Thu, May 29, 2008 at 06:11:04PM -0700, Thomas Hartman wrote:
> After a little drama with zlib, I managed to get cabal-install installed.
> 
> I then attempted to do
> 
> cabal install HAppS-Server
> 
> since this is a module with a lot of dependencies, and in rapid
> development flux, so perenially painful for me to install.
> 
> The result is that I managed to install everything up to HAppS-State,
> which I think is the last dependency, but then seemed to hang
> indefinitely in the middle of installing HAppS-Server at the end.
> 
> OK, I thought, then perhaps I can do normal runghc Setup.hs after
> downloading and unzipping the tar from
> 
> http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HAppS-Server-0.9.2.1
> 
> However, this resulted in error
> 
> thartman at thartman-laptop:~/haskellInstalls/smallInstalls/HAppS-Server-0.9.2.1>runghc
> Setup.hs configure
> ...
> Setup.hs: At least the following dependencies are missing:
> HAppS-Data >=0.9.2...
> 
> Strange, because I had just installed that module via cabal-install,
> and I could load it in ghci with :m +HappS.Data.

'cabal install' installs packages to your user database by default.  However,
'Setup configure' only uses packages from the global database unless the --user
flag is passed.

> I then ran ghc-pkg and got this strange result that my packages were
> broken into two different files. Is this by design?
> 
> ghc-pkg list
> /usr/local/lib/ghc-6.8.2/package.conf:
>     Cabal-1.2.3.0, Cabal-1.3.11, Cabal-1.5.2, DeepArrow-0.2,
> ....
> /home/thartman/.ghc/i386-linux-6.8.2/package.conf:
>     HAppS-Data-0.9.2.1, HAppS-IxSet-0.9.2.1, HAppS-State-0.9.2.1,

Yep, this is by design.  The first is a global database that will require root
access to modify.  The second is your user database which you can modify
without root access.

> I am curious if anybody else is able to install HAppS-Server using
> cabal install, and whether they can shed any light on the other isuses
> I raised.
> 
> Thomas.

I tried building HAppS-server the other day, and had a similar experience.  It
seems that HAppS uses some incredibly elaborate TH/typeclass hacks that take
gobs of resources to compile -- my box actually ran out of memory attempting to
build it.


Cheers,
Spencer Janssen