[Haskell-cafe] errors while installing yesod 0.8

[Rogan Creswick]

On Tue, Apr 19, 2011 at 3:10 PM, Michael Litchard <michael at schmong.org> wrote:
> New information, may be helpful.
>
> I manually installed hamlet 0.8 with cabal-dev, and it seemed to
> install. Here is the message
>
>
> Registering hamlet-0.8.0...
> Installing library in
> /home/mlitchard/hamlet-0.8.0/cabal-dev//lib/hamlet-0.8.0/ghc-6.12.3
> Registering hamlet-0.8.0...

It looks like you manually downloaded the hamlet-0.8.0.tar.gz,
unpacked it, and ran cabal-dev install from inside there -- is that
right? (There's nothing wrong with doing it that way, but it doesn't
quite do what you expected, based on the rest of your email.  Also, if
my assumption is wrong, then the rest of my advice may not help.)

First, it's important to know that cabal-dev sandboxes everything it
can.  If you want to install hamlet into your .cabal directory, then
you need to use cabal, not cabal-dev.  Cabal-dev is meant to keep
everything for a given project separate from everything else -- in
this way you can have multiple projects that depend on conflicting
libraries building at the same time, and it also means that
coincidental changes to your user package database won't cause
spurious *successes* when you build something, which is a surprisingly
common problem.  Unfortunately this means that the first time you
build a project with cabal-dev, it tends to take a long time (it has
to build everything it depends on).

Now, there are (at least) two important take-away points /
implications of using cabal-dev:

 (1) cabal-dev won't install a library into a standard location.
That's by design, so you don't usually want to cabal-dev install
dependencies manually.
 (2) cabal-dev uses the local hackage cache to select packages in the
same way cabal does (cabal-dev actually just uses cabal to do this).

> mlitchard at apotheosis:~/yesod-0.8.0$ cabal-dev install
> Resolving dependencies...
> cabal: cannot configure yesod-0.8.0. It requires hamlet ==0.8.*
> There is no available version of hamlet that satisfies ==0.8.*

I think you just need to run 'cabal update' so cabal-dev can see the
latest version of hamlet, after which you can cabal-dev install yesod.

There are a couple other things to try if that doesn't work for some reason.

--Rogan


>
> I noticed it did not install in the $HOME/.cabal/ path. How do make
> sure it does that?
> I think if I can get it to install in the right place this will work out.
>
> On Tue, Apr 19, 2011 at 2:52 PM, Rogan Creswick <creswick at gmail.com> wrote:
>> On Tue, Apr 19, 2011 at 2:18 PM, Michael Litchard <michael at schmong.org> wrote:
>>> mlitchard at apotheosis:~/monad-control$ cabal install
>>> Resolving dependencies...
>>> Configuring monad-control-0.2.0.1...
>>> cabal: Error: some packages failed to install:
>>> monad-control-0.2.0.1 failed during the configure step. The exception was:
>>> ExitFailure 11
>>>
>>>
>>> note: I've been trying to use the cab command to manage my packages, I
>>> get the same error as above when I use cab instead of cabal.I mention
>>> this just in case there is some unforseen problem having to do with
>>> cab/cabal interaction.
>>>
>>> Has anyone experienced this problem, or know what I can do to get more
>>> useful error messages that might reveal the cause of the breakage?
>>
>> You might learn more by issuing the configure / build steps manually
>> (I think `cabal configure` will produce an error).  Upping the
>> verbosity will also help:
>>
>> # get pages and pages of details:
>> $ cabal install --verbose=3
>>
>> I would first suggest trying cabal-dev, though (cab can delegate to
>> cabal-dev now too, but I haven't played with it yet).
>>
>> $ cabal-dev install yesod-0.8
>>
>> will either work or fail in a way that we can more easily reproduce.
>>
>> --Rogan
>>
>