(Imported from Trac #550, reported by @dcoutts on 2009-04-29)
As reported by a user:
when I run cabal update I get some strange error:
% cabal update
Downloading the latest package list from hackage.haskell.org
cabal: user error (openTCPConnection: host lookup failure for "")
The problem with the error of course is that we've no idea what it is it thinks is "", there's no indication that it's the proxy. If it said that it encountered the problem while contacting the proxy that'd be an improvement.
(Imported comment by @kosmikus on 2009-04-29)
Verified that this still exists.
Partial Fix #543 by handling empty HTTP proxy uris