id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	difficulty	ghcversion	platform
758	expose existing functionality: fetchPackage/unpackPackage	claus		"`cabal-install` has functionality for fetching and unpacking `cabal` packages (`.tar.gz`, as produced by `cabal sdist`).

It would be very helpful to expose these functions as `cabal-install` commands. `unpackPackage` is the more important of the two, though being able to fetch individual packages from URLs (think blogs, wikis, ..) without having to establish a full hackage-like repo would also be very welcome.

Most importantly, you could remove the whole http://www.haskell.org/haskellwiki/How_to_unpack_a_tar_file_in_windows hazzle. Instead of package authors and users having to worry about whether some unpacker is installed client-side, everyone could just rely on
{{{
cabal unpack Example.tar.gz
}}}"	enhancement	closed	normal		cabal-install tool	1.8.0.6	normal	duplicate			unknown