[Hackage] #507: display available flags based on the .cabal file

[Hackage]

#507: display available flags based on the .cabal file
---------------------------------+------------------------------------------
  Reporter:  guest               |        Owner:         
      Type:  enhancement         |       Status:  new    
  Priority:  normal              |    Milestone:         
 Component:  cabal-install tool  |      Version:  1.6.0.1
  Severity:  minor               |   Resolution:         
  Keywords:                      |   Difficulty:  normal 
Ghcversion:                      |     Platform:         
---------------------------------+------------------------------------------
Changes (by duncan):

  * difficulty:  unknown => normal

Comment:

 Right. Should not be too hard. After all we do this already in the `cabal
 info` output. eg:

 {{{
 $ cabal info darcs
 * darcs            (program and library)
     Synopsis:      a distributed, interactive, smart revision control
 system

 [..snip..]

     Source repo:   http://darcs.net/
     Executables:   darcs
     Flags:         curl, curl-pipelining, libwww, http,
                    external-bytestring, external-zlib, haskeline,
                    terminfo, curses, type-witnesses, color, base3
 }}}

 Of course when configuring a single package we want to see the description
 of each of these flags, if they're available.

 We could do similarly for `cabal info` when run in the current dir with a
 local .cabal package. Printing it in `cabal configure --help` is
 technically a bit harder. Perhaps the help string for `--flags` should
 refer to `cabal info`. Or perhaps that's just to annoying and we should
 work out how to get it to read the local `.cabal` file before producing
 the help output (but not failing if one is not present or if it cannot be
 parsed).

-- 
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/507#comment:1>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects