On 10/25/06, Duncan Coutts
On Wed, 2006-10-25 at 09:39 -0500, Brian Smith wrote:
Name: foo Version: 1.0
configuration: flag(debug) Name: foo-debug
Otherwise, how can I have a debug and an optimized configuration of a given library installed at the same time?
You can't. No current Haskell implementation supports this (without doing things manually like using separate package databases / search paths).
What you want is what the ghc build system refers to as a 'way'. It's a whole other discussion I think.
Yes, I am interested in building with different "ways" as you say. But, I think one of your examples used -DDEBUG. I think it is reasonable to want to install regular and debug versions of a package together. You said that no current Haskell implementation supports what I proposed. But, isn't this purely a Cabal issue. If I give a -debug flag to Cabal, and Cabal allows me to rename the package to foo-debug (by allowing me to put a name entry in the configuration stanza, like in my example), then foo and foo-debug can sit right next to each other in GHC or Hugs (at least). The user would do: runhaskell Setup.lhs configure -debug runhaskell Setup.lhs build runhaskell Setup.lhs install Now, foo-debug is installed. Then: runhaskell Setup.lhs configure runhaskell Setup.lhs build runhaskell Setup.lhs install Now, foo is installed too. Then, we can make packages that depend on either foo or foo-debug using the mechanism you proposed. Configuration: flag(debug) Name: bar-debug Build-depends: foo-debug || foo Configuration: !flag(debug) Name: bar Build-depends: foo The only extension to your idea is being able to change the name of the installed package in the configuration. I think that this is a very desirable feature because it allows people to build packages with names that uniquely identify the configuration, if the choose to do so. Regards, Brian