[Hackage] #697: Add "cabal install --only-dependencies" flag

[Hackage]

#697: Add "cabal install --only-dependencies" flag
---------------------------------+------------------------------------------
  Reporter:  igloo               |        Owner:      
      Type:  enhancement         |       Status:  new 
  Priority:  normal              |    Milestone:      
 Component:  cabal-install tool  |      Version:  HEAD
  Severity:  major               |     Keywords:      
Difficulty:  unknown             |   Ghcversion:      
  Platform:                      |  
---------------------------------+------------------------------------------

Comment(by j3h):

 Please excuse the accidental double form submission, the two attached
 files are identical. The patch implements an `--only-dependencies` flag
 for the `install` command.

 My resolution for the case that Duncan described above, where a user
 requests dependencies only and then specifies a necessary dependency on
 the command line, installation fails with an error message. In addition to
 the options that Duncan mentioned for this case, there is a third option,
 which is to install only the dependencies that can be satisfied
 ''without'' installing any explicitly mentioned package. The behavior in
 this case is not very important to me, because I expect only to use this
 flag when actively developing a package, so the only excluded package
 would be the root of the dependency DAG, which can always be safely
 removed.

 It occurs to me as well that another sensible interface to this
 functionality (especially for development purposes) would be
 {{{
 cabal configure --install-missing-dependencies
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/697#comment:3>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects