On Fri, 2008-06-13 at 16:54 -0400, Darrin Thompson wrote:

I'm reposting this here as something bad appeared to happen to my post on haskell-cafe and I probably should have posted here anyway.

It did make it though and here is the reply that I posted to haskell-cafe. Further to that, do feel free to add a feature request ticket to suggest the we look into doing the configure phase of every package before doing the build phase of any: http://hackage.haskell.org/trac/hackage/

Configuring yi-0.3... Warning: Instead of 'ghc-options: -DDYNAMIC -DFRONTEND_VTY' use 'cpp-options: -DDYNAMIC -DFRONTEND_VTY' setup: alex version >=2.0.1 && <3 is required but it could not be found. cabal: Error: some packages failed to install: yi-0.3 failed during the configure step. The exception was: exit: ExitFailure 1

Is this a cabal problem of package problem? I would have expected it to fail immediately instead of discover this problem so far into process.

So it's failing when configuring yi because alex is not installed. So the question is when should this get checked? I think it's not unreasonable to have the check where it is now though perhaps we could do better by bringing it forward. The point is, cabal-install only checks that haskell packages are available before beginning to install stuff. It leaves all the other checks (build tools, C libs, custom checks in Setup.hs script etc) to be done at the configure phase of each package. In theory it's not impossible to imagine doing the configure phase of every package before doing the build phase of any package but it's not clear that it gains us that much and it's a bit more complex to do it that way. Duncan