Stackage.Environment

[chrisdone]

We'll need some functionality for determining the right environment variables based on the configuration. Making this issue to track any discussion needed.

-- | Handling of environment variables, such as the PATH,
-- GHC_PACKAGE_SANDBOX, etc.
module Stackage.Environment where
getEnvironmentVariables :: (MonadLogger m,MonadIO m,MonadThrow m)
                        => Config -> m (Map Text Text)
getPATH :: (MonadLogger m,MonadIO m,MonadThrow m)
        => Config -> m Text
withConfiguredEnvironment :: (MonadLogger m,MonadIO m,MonadThrow m)
                          => Config -> (m a -> m a) -> m a

[snoyberg]

One point along the lines of GHC_PACKAGE_SANDBOX: cabal (IMO quite mistakenly) refuses to work if that variable is set. What would make more sense would be to instead parse the variable and pass the appropriate values to GHC. Perhaps that's something we should be fixing here to make our tooling more composable: if that environment variable is set, do the parsing and update the package databases, and automatically strip that environment variable when calling the Cabal library. This way, it would be possible, for example, to run stackage build from inside a stackage shell.

[chrisdone]

due the parsing

I must've re-read that sentence about 5 times. This approach makes sense to me.

[snoyberg]

Doh, edited.

[snoyberg]

@chrisdone This can be closed based on conversations today, correct?

[chrisdone]

Yep.