CODEWITHSUNDEEP
haskellcabalhaskell-stack
Sebastian Graf
Sebastian Graf

Reputation: 3740

Override the cabal version of an LTS

I have a project that I want to compile with LTS 2, but I'm stuck trying to work around this well-known bug in OS X 10.11.

Can I somehow specify a newer version of Cabal to use with ghc-7.8.4? Note that the project only really compiles with GHC 7.8.*.

Edit:

Really meant Cabal, not cabal-install.

Edit 2:

Actually, the answer to this question doesn't really solve my concrete problem (compiling helium, which requires GHC <= 7.8.4), because the bug is not specific to Cabal, but rather to unix, which GHC < 7.10 depends upon.

Upvotes: 3

Views: 165

Answers (3)

Sebastian Graf
Sebastian Graf

Reputation: 3740

As noted in Michael Snoyman's comment, there is stack setup --upgrade-cabal to do just that. That's it for the answer to this question.

In my specific case (XY problem), for that to work I had to do the usual work-around for that El Capitano related bug, which is explained here. So I enabled rootless, ran the upgrade command and re-enabled rootless.

To no avail I'm afraid: The bug is specific to unix < 2.7.1.0, which GHC 7.8.4 also depends on. So even after upgrading cabal, I can't compile anything in lts-2 unless I disable rootless, which is pretty annoying.

Actually it's kinda depressing that the GHC folks decided not to file a new minor release with the updated unix package. This means that no realistic/recent OS X configuration can build anything which involves GHC < 7.10.

Upvotes: 1

ErikR
ErikR

Reputation: 52059

Here's a recipe for installing ghc-7.8.4 into the directory of your choice:

  1. Download the "bindist" from https://www.haskell.org/ghc/download_ghc_7_8_4#macosx_x86_64
  2. Untar it into a scratch directory
  3. Create the destination directory, e.g. $HOME/my-prefix.

  4. In the scratch directory run:

    $ ./configure --prefix=$HOME/my-prefix
$ make install

Now ghc may be found in $HOME/my-prefix/bin.

Upvotes: 1

Kostia R
Kostia R

Reputation: 2565

I think the problem is related not just to Cabal library version (btw, stack doesn't use or need cabal-install), but also to GHC version. Stack's FAQ mentions an item about this error, but I think it didn't help for me and I just upgraded to 7.10.2 at the time.

Upvotes: 1

Related Questions