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Comment by papsosouid | Hacker News Reader

I'm writing 3 different web apps, plus some command line tools in haskell. I have been working on these projects for a year now, and I've never seen any cabal problems that aren't typical problems that occur with any package manager (trying to install conflicting modules).

    $ ghc-pkg list | wc -l
         182

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I felt that way up until last week! I somehow felt I was special, that cabal-hellfires had burnt a ring around me. Then next thing I knew I had a 4 page cabal conflict problem and had to just toast .ghc and .cabal and start over.

It's a real problem.

use Cabal-Dev!

Also the next major release of cabal should have a lot of the cabal-dev machinery baked in. Theres also active brain storming by GHC dev folks on how to make things better on the compiler side too.

Your response makes it sound like you just had a simple problem like you get with any language, and followed bad advice on solving it based on the assumption that "cabal is just bad and you have to do this". The big give away is that you didn't need to delete your .cabal directory, advice to do so is coming from someone who doesn't know the basics of how cabal works. It is just storing downloaded sources, all deleting it accomplishes is making you re-download stuff for no reason. The installed packages are in your .ghc directory. Cabal is no more broken than cpan.

You're right that I'm not very fluent on how Cabal works. It worked well enough that I didn't really need to until recently. I'm not claiming either that CPAN is better than Cabal. Could versioning be done better? Probably. I don't even claim to know enough to have a competent suggestion as to how, though.

Doesn't mean things don't break, though.

>Doesn't mean things don't break, though.

Right. The issue is that cabal has unfairly developed a reputation as being broken. People always say stuff like "every other language has this sorted out, why is haskell so bad at it?". When the reality is that the problems you get with cabal are the same ones you get with cpan or pip or anything else.

They're slightly exacerbated in that Cabal/GHC/Haskell type checks and thus has a higher likelihood of discovering mismatches.

you could look into hsenv and cabal-dev.

https://github.com/cakesolutions/the-pragmatic-haskeller

http://bob.ippoli.to/archives/2013/01/11/getting-started-wit...

Also, problems in the haskell ecosystem don't stay problems for long, this one is the longer end of the tail

http://alpmestan.com/posts/2012-11-02-cabal-hackage-what-you...

I do use .hsenv a lot, but for simple playing around with libraries (where I'm also most likely to hit major version overlaps) I liked to keep installing packages into the user level database.

Don't want to turn this into Stack Exchange and this may be homebrew's fault on OS X but I just tried installing 'haskell-platform' and got:

  Error:
  Building the QuickCheck-2.5.1.1 package failed
  make: *** [build.stamp] Error 2

Ok I will install the package on haskell.org, which instructs me to 'To upgrade, run: cabal install cabal-install':

  ...

  cabal: Error: some packages failed to install:
  cabal-install-1.16.0.2 failed during the building phase. The exception was:
  ExitFailure 1

Alright, maybe I don't really need the update, let's try yesod:

  cabal: Error: some packages failed to install:
  ReadArgs-1.2.1 depends on system-filepath-0.4.7 which failed to install.
  aeson-0.6.1.0 depends on hashable-1.2.0.5 which failed to install.
  asn1-data-0.7.1 failed during the building phase. The exception was:
  ExitFailure 1
  attoparsec-0.10.4.0 failed during the building phase. The exception was:
  ExitFailure 1
  attoparsec-conduit-1.0.0 depends on transformers-base-0.4.1 which failed to
  install.
  authenticate-1.3.2.6 depends on zlib-bindings-0.1.1.3 which failed to install.
  base64-conduit-1.0.0 depends on transformers-base-0.4.1 which failed to
  install.
  basic-prelude-0.3.4.0 depends on transformers-base-0.4.1 which failed to
  install.
  blaze-builder-0.3.1.0 failed during the building phase. The exception was:
  ExitFailure 1
  blaze-builder-conduit-1.0.0 depends on transformers-base-0.4.1 which failed to
  install.
  blaze-html-0.6.0.0 depends on blaze-builder-0.3.1.0 which failed to install.
  blaze-markup-0.5.1.4 depends on blaze-builder-0.3.1.0 which failed to install.
  case-insensitive-1.0 depends on hashable-1.2.0.5 which failed to install.
  certificate-1.3.5 depends on crypto-api-0.11 which failed to install.
  classy-prelude-0.5.3 depends on transformers-base-0.4.1 which failed to
  install.
  clientsession-0.8.1 depends on crypto-api-0.11 which failed to install.
  conduit-1.0.2 depends on transformers-base-0.4.1 which failed to install.
  cookie-0.4.0.1 depends on blaze-builder-0.3.1.0 which failed to install.
  cprng-aes-0.3.4 depends on crypto-api-0.11 which failed to install.
  crypto-api-0.11 failed during the building phase. The exception was:
  ExitFailure 1
  crypto-conduit-0.5.0 depends on transformers-base-0.4.1 which failed to
  install.
  crypto-pubkey-0.1.2 depends on crypto-api-0.11 which failed to install.
  cryptohash-0.8.3 depends on crypto-api-0.11 which failed to install.
  css-text-0.1.1 depends on attoparsec-0.10.4.0 which failed to install.
  email-validate-1.0.0 depends on attoparsec-0.10.4.0 which failed to install.
  failure-0.2.0.1 failed during the building phase. The exception was:
  ExitFailure 1
  fast-logger-0.3.1 depends on blaze-builder-0.3.1.0 which failed to install.
  filesystem-conduit-1.0.0 depends on transformers-base-0.4.1 which failed to
  install.
  fsnotify-0.0.6 depends on system-filepath-0.4.7 which failed to install.
  hamlet-1.1.6.3 depends on shakespeare-1.0.3.1 which failed to install.
  hashable-1.2.0.5 failed during the building phase. The exception was:
  ExitFailure 1
  hfsevents-0.1.3 failed during the building phase. The exception was:
  ExitFailure 1
  hjsmin-0.1.4.1 depends on blaze-builder-0.3.1.0 which failed to install.
  hspec-1.4.4 failed during the building phase. The exception was:
  ExitFailure 1
  html-conduit-1.1.0 depends on xml-types-0.3.3 which failed to install.
  http-conduit-1.9.0 depends on zlib-bindings-0.1.1.3 which failed to install.
  http-date-0.0.4 depends on attoparsec-0.10.4.0 which failed to install.
  http-reverse-proxy-0.1.1.3 depends on zlib-bindings-0.1.1.3 which failed to
  install.
  http-types-0.8.0 depends on hashable-1.2.0.5 which failed to install.
  language-javascript-0.5.7 depends on blaze-builder-0.3.1.0 which failed to
  install.
  lifted-base-0.2.0.2 depends on transformers-base-0.4.1 which failed to
  install.
  mime-mail-0.4.1.2 depends on blaze-builder-0.3.1.0 which failed to install.
  mime-types-0.1.0.3 failed during the building phase. The exception was:
  ExitFailure 1
  monad-control-0.3.1.4 depends on transformers-base-0.4.1 which failed to
  install.
  monad-logger-0.3.0.1 depends on transformers-base-0.4.1 which failed to
  install.
  network-conduit-1.0.0 depends on transformers-base-0.4.1 which failed to
  install.
  optparse-applicative-0.5.2.1 failed during the building phase. The exception
  was:
  ExitFailure 1
  path-pieces-0.1.2 failed during the building phase. The exception was:
  ExitFailure 1
  pem-0.1.2 depends on attoparsec-0.10.4.0 which failed to install.
  persistent-1.1.5.1 depends on transformers-base-0.4.1 which failed to install.
  persistent-template-1.1.2.4 depends on transformers-base-0.4.1 which failed to
  install.
  pool-conduit-0.1.1 depends on transformers-base-0.4.1 which failed to install.
  project-template-0.1.3 depends on transformers-base-0.4.1 which failed to
  install.
  publicsuffixlist-0.0.3 failed during the building phase. The exception was:
  ExitFailure 1
  pureMD5-2.1.2.1 depends on crypto-api-0.11 which failed to install.
  pwstore-fast-2.3 depends on crypto-api-0.11 which failed to install.
  resource-pool-0.2.1.1 depends on transformers-base-0.4.1 which failed to
  install.
  resourcet-0.4.5 depends on transformers-base-0.4.1 which failed to install.
  shakespeare-1.0.3.1 failed during the building phase. The exception was:
  ExitFailure 1
  shakespeare-css-1.0.3 depends on shakespeare-1.0.3.1 which failed to install.
  shakespeare-i18n-1.0.0.2 depends on shakespeare-1.0.3.1 which failed to
  install.
  shakespeare-js-1.1.2.1 depends on shakespeare-1.0.3.1 which failed to install.
  shakespeare-text-1.0.0.5 depends on shakespeare-1.0.3.1 which failed to
  install.
  simple-sendfile-0.2.11 failed during the building phase. The exception was:
  ExitFailure 1
  skein-0.1.0.12 depends on crypto-api-0.11 which failed to install.
  socks-0.5.0 failed during the building phase. The exception was:
  ExitFailure 1
  system-fileio-0.3.11 depends on system-filepath-0.4.7 which failed to install.
  system-filepath-0.4.7 failed during the building phase. The exception was:
  ExitFailure 1
  tagsoup-0.12.8 failed during the building phase. The exception was:
  ExitFailure 1
  tagstream-conduit-0.5.4 depends on transformers-base-0.4.1 which failed to
  install.
  tls-1.1.2 depends on crypto-api-0.11 which failed to install.
  tls-extra-0.6.1 depends on crypto-api-0.11 which failed to install.
  transformers-base-0.4.1 failed during the building phase. The exception was:
  ExitFailure 1
  unordered-containers-0.2.3.0 depends on hashable-1.2.0.5 which failed to
  install.
  vault-0.2.0.4 depends on hashable-1.2.0.5 which failed to install.
  wai-1.4.0 depends on transformers-base-0.4.1 which failed to install.
  wai-app-static-1.3.1.2 depends on transformers-base-0.4.1 which failed to
  install.
  wai-extra-1.3.2.4 depends on zlib-bindings-0.1.1.3 which failed to install.
  wai-logger-0.3.0 depends on transformers-base-0.4.1 which failed to install.
  wai-test-1.3.0.4 depends on transformers-base-0.4.1 which failed to install.
  warp-1.3.7.4 depends on transformers-base-0.4.1 which failed to install.
  xml-conduit-1.1.0.3 depends on xml-types-0.3.3 which failed to install.
  xml-types-0.3.3 failed during the building phase. The exception was:
  ExitFailure 1
  xss-sanitize-0.3.3 depends on tagsoup-0.12.8 which failed to install.
  yaml-0.8.2.3 depends on transformers-base-0.4.1 which failed to install.
  yesod-1.1.9.2 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-auth-1.1.5.3 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-core-1.1.8.2 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-default-1.1.3.2 depends on zlib-bindings-0.1.1.3 which failed to
  install.
  yesod-form-1.2.1.3 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-json-1.1.2.1 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-persistent-1.1.0.1 depends on zlib-bindings-0.1.1.3 which failed to
  install.
  yesod-platform-1.1.8 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-routes-1.1.2 depends on path-pieces-0.1.2 which failed to install.
  yesod-static-1.1.2.2 depends on zlib-bindings-0.1.1.3 which failed to install.
  yesod-test-0.3.5 depends on xml-types-0.3.3 which failed to install.
  zlib-bindings-0.1.1.3 failed during the building phase. The exception was:
  ExitFailure 1
  zlib-conduit-1.0.0 depends on zlib-bindings-0.1.1.3 which failed to install.

If I'm yak-shaving in my first hour of trying a language out it's not a good sign.

You have to scroll back to see the actual error. That could be anything from missing C libraries to a permission problem.

I'm sure it's fixable, it's just not the best first impression for those new to the ecosystem :) I love trying out new languages (prag pubs 7 languages in 7 days is great) but for production work I want to know that down the line if I need lib x, it won't be hard to find and even more importantly it will just work (or the googles machine will lead me in the right direction).

I actually stayed away from Scala for a while for this reason. SBT would blow up left and right. It's more mature now and with Play you can build performant web apps very quickly.

My point is not "it is fixable". My point is you didn't look at the error and just decided "shit's broken". Your problem is with 99.999999% certainty a simple problem that is unrelated to cabal. The fact that it is possible to see an error does not indicate that there is some uncertainty about whether or not you will be able to install lib x.

I do not think ghc/haskell-platform targets homebrew, as most programs/libraries do not right?

So some amount of leg work is bound to come up if you install many packages through homebrew.

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