Bug#868591: haskell-lens-aeson FTBFS: Failed to load interface for Data.Aeson.Encoding.Internal

[Adrian Bunk]

Source: haskell-lens-aeson
Version: 1.0.1-1
Severity: serious

https://buildd.debian.org/status/package.php?p=haskell-lens-aeson

...
[1 of 1] Compiling Data.Aeson.Lens  ( src/Data/Aeson/Lens.hs, dist-ghc/build/Data/Aeson/Lens.o )
/usr/lib/haskell-packages/ghc/lib/x86_64-linux-ghc-8.0.2/aeson-1.0.2.1-CgbEAGwJWkq5wCUqDjmFHU/Data/Aeson.hi
Declaration for encode
Unfolding of encode:
  Failed to load interface for `Data.Aeson.Encoding.Internal'
  There are files missing in the `aeson-1.0.2.1' package,
  try running 'ghc-pkg check'.
  Use -v to see a list of the files searched for.
/usr/lib/haskell-packages/ghc/lib/x86_64-linux-ghc-8.0.2/aeson-1.0.2.1-CgbEAGwJWkq5wCUqDjmFHU/Data/Aeson/Types/ToJSON.hi
Declaration for $fToJSONValue
Class ops for dfun $fToJSONValue:
  Can't find interface-file declaration for variable value
    Probable cause: bug in .hi-boot file, or inconsistent .hi file
    Use -ddump-if-trace to get an idea of which file caused the error
/usr/lib/haskell-packages/ghc/lib/x86_64-linux-ghc-8.0.2/aeson-1.0.2.1-CgbEAGwJWkq5wCUqDjmFHU/Data/Aeson/Types/ToJSON.hi
Declaration for ToJSON
Class op toEncoding a -> Encoding ty:
  Can't find interface-file declaration for type constructor or class Encoding
    Probable cause: bug in .hi-boot file, or inconsistent .hi file
    Use -ddump-if-trace to get an idea of which file caused the error
Cannot continue after interface file error
/usr/share/cdbs/1/class/hlibrary.mk:147: recipe for target 'build-ghc-stamp' failed
make: *** [build-ghc-stamp] Error 1