Spot on, Kim-Ee.  Thanks.  unsetting http_proxy fixed it.

I’m fwding to cabal-devel: it would be great that if “http_proxy” was set to “”, then it behaved just as if it was un-set.  The current behaviour is very confusing (to me anyway).

Simon

From: Kim-Ee Yeoh [mailto:ky3@atamo.com]
Sent: 08 May 2014 14:48
To: Simon Peyton Jones
Cc: Herbert Valerio Riedel; Simon Marlow; ghc-devs@haskell.org
Subject: Re: Cabal can't open a TCP connection

On Thu, May 8, 2014 at 8:22 PM, Simon Peyton Jones <simonpj@microsoft.com> wrote:

On a machine that doesn't need to use a proxy server, what should $http_proxy be set to?

It's a Maybe (Maybe String) problem. Blame Cabal for not ignoring an empty http_proxy. The *nix programs I've tried treat empty as unset.

The solution is: unset HTTP_PROXY.

-- Kim-Ee

---

Från: Simon Peyton Jones
Skickat: 2014-05-08 14:04
Till: ghc-devs@haskell.org
Kopia: Simon Marlow
Ämne: Cabal can't open a TCP connection

Dear ghc-devs

Cabal can’t open a TCP connection from my Linux box.  It used to work fine.  Here’s what it says:

cabal -v3 update

Downloading the latest package list from hackage.haskell.org

Sending:

GET http://hackage.haskell.org/packages/archive/00-index.tar.gz HTTP/1.1

User-Agent: cabal-install/1.16.0.2

Host: hackage.haskell.org

proxy uri host: , port:

Creating new connection to

cabal: openTCPConnection: host lookup failure for ""

simonpj@cam-05-unx:~/code/HEAD$ cabal --version

cabal-install version 1.16.0.2

using version 1.16.0.3 of the Cabal library

simonpj@cam-05-unx:~/code/HEAD$

Can anyone help me work out what to do?  git works just fine, so the internet is connected all right.

Thanks

Simon