[PATCH] Print a more friendly message when http_proxy is down.

[Mikhail Glushenkov]

Hi,

On 26 July 2014 00:20, Nikita Karetnikov <nikita at karetnikov.org> wrote:
> An attempt to fix #1962.  I think the exception comes from ‘connect’ in
> ‘Network.Socket’.

Perhaps it's better to solve this in HTTP itself? It gives decent
error messages in other cases:

$ export HTTP_PROXY=foo
$ cabal update
Downloading the latest package list from hackage.haskell.org
cabal: openTCPConnection: host lookup failure for "foo"

$ export HTTP_PROXY=http://localhost:3128
$ cabal update
Downloading the latest package list from hackage.haskell.org
cabal: does not exist