[arch-haskell] ghc: /usr/share/doc/ghc/html/libraries/hslogo-16.png exists in filesystem

Mateusz Loskot mateusz at loskot.net
Tue Oct 16 01:32:12 CEST 2012

On 15 October 2012 20:51, Magnus Therning <magnus at therning.org> wrote:
> On Mon, Oct 15, 2012 at 05:16:24PM +0100, Mateusz Loskot wrote:
> [...]
>> As Haskell newbie and new born Hakyll users, I've found recent
>> replies [1] by Ian Ross interesting:
>> "I'm also using Arch Linux on x86_64.  I would strongly recommend
>> *not* using the Arch packages for most Haskell things.  I use hsenv
>> instead."
>> I haven't switched myself and I still use the packages, but I
>> started to wonder if Ian's got the point indeed.
>> [1] https://groups.google.com/d/topic/hakyll/9G1qXBA4raU/discussion
> As so often it all depends on what your goal is.  hsenv compares
> itself to Python's virtualenv[1].  I've personally written quite a bit
> of Python code, and used many tools and programs written in Python,
> without *ever* feeling a need to use virtualenv.  The same is, so far
> at least, true regarding Haskell and hsenv.  In neither language have
> I ever had the need to have more than a single environment around.

Same here, I've written plenty of Python code and never used virualenv.
But, I didn't target multi-user environments like Web with those programs.

> On the other hand I've often had a need to install libraries on my
> system.  In those cases I personally prefer using the package
> manager to make libraries available to all users on my system, i.e. I
> don't use distutils and cabal to install things on my system, just as
> I don't download tar-balls and run 'sudo make install' (instead I wrap
> that up in a PKGBUILD and install the resulting package).

Yes, I have impression that's the right way.
Especially for, let's say, single end-user cases.

> On the other hand I completely understand why virtualenv/hsenv are
> useful in some cases.  By creating a virtual environment they
> disconnect you from the whims of upstream (Arch & ArchHaskell),
> letting you create the exact environment you need and run 'pacman
> -Syu' without having to worry (too much) about breaking that service
> your livelihood depends on.

For example, if on servers, for Web development, I imagine virtualenv
or generally *env approach is necessary, especially in production.

Thanks for useful comments.

Best regards,
Mateusz Loskot, http://mateusz.loskot.net

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