cabal install should recognize if package was already configured

[bos]

(Imported from Trac #309, reported by bfr on 2008-07-05)

If I first configure an unpacked package inside its source directory

cabal configure --prefix=/my/path --flags=whatever

and then afterwards do

cabal install

then the configure options I gave before are not recognized by the 'cabal install'.

Instead, 'cabal install' without a package name argument should inspect whether the package is already configured and use whatever options have been set.

[bos]

(Imported comment by @dcoutts on 2008-07-05)

Checking if it is already configured is not easy in general. However we should be able to just remember what config flags were used. See #294.

[bos]

(Imported comment by @dcoutts on 2009-03-09)

Wed Aug 25 14:11:06 BST 2010  Dmitry Astapov <[email protected]>
- Auto-reconfiguration when .cabal is newer than setup-config
  This patch adds "ConfigFlags" to the "LocalBuildInfo" and reuses them to
  perform "configureAction" when .cabal file is changed. This has
  the same effect as re-running "configure" with the most recent used
  set of options, which should be the sensible thing to do.
  Closes #294, #477, #309 and #518.
  

I have not yet checked if it actually fixes this ticket though. I think this one might be more tricky than the others.

[bos]

(Imported comment by @kosmikus on 2010-10-12)

I don't think this is fixed yet. At least dependency resolution happens on "cabal install", not taking previous flag choices into account. Personally, I'm not sure if "cabal install" should be as stateful as is desired here.

[ezyang]

Yeah, we're not going to do this.