Simon Hengel

@lfairy I think it is preferable to only have `base` as a dependency for `data-default` and keep the other instances (`containers`, `dlist`, `old-locale`) orphan. Every dependency adds a cost, so...

There are some issues that I have to resolve. I'm working on it, sorry for the delay.

`doctest-0.9.4` has support for `HASKELL_PACKAGE_SANDBOX`.

Would it make sense to set `GHC_PACKAGE_PATH` before running the tests, instead? Similar to fpco/stackage@2534579.

@snoyberg Ah ok, I see what you mean. `cabal-dev` does not wrap the commands individually, so there is currently no easy way to tell whether it's `cabal-dev test`.

@dag as I understand it this invariant is violated by other functions too, specifically `show`, `map` and `traverse`. I'm tempted to close this as `wontfix`.

@ethercrow If you have a data type, you can use GHCs generics to get instances for free: ``` {-# LANGUAGE DeriveGeneric #-} module Person where import GHC.Generics import Data.Aeson data...

If you can define a mapping from record field names to JSON names (e.g. striping a prefix or converting `CamelCase` to `snake_case`) you can still use `genericToJSON`/`genericParseJSON` with custom options....

@shell could we just not look at the cabal file at all and use `cabal exec` for sandbox support?

^ @schell sorry, wrong mention...