After removing some directories in store cabal calls error without proper description.

```
Build profile: -w ghc-7.10.3 -O0
In order, the following will be built (use -v for more details):
- containers-0.5.11.0 (lib) (requires build)
- monad-control-0.3.3.0 (lib:monad-control) (requires build)
internal error in InstallPlan.completed
CallStack (from HasCallStack):
error, called at ./Distribution/Client/InstallPlan.hs:262:25 in main:Distribution.Client.InstallPlan
```

Note: I'm trying to cleanup somehow inconsitent store because I got

```
Resolving dependencies...
Build profile: -w ghc-7.10.3 -O0
In order, the following will be built (use -v for more details):
- async-pool-0.8.0 (lib) (first run)
Configuring library for async-pool-0.8.0..
cabal: The following package dependencies were requested
--dependency='monad-control=monad-control-0.3.3.0-7aba405eb6ac318d507aceb932b2265ec63f2019aadfc5d128d46fcbe3da3be8'
however the given installed package instance does not exist.
```

---

There should be a way to *repair* store, in my use case wiping the whole store is very expensive and isn't really an option in general.