Resolving dependencies...
Configuring packedstring-0.1.0.1...
Building packedstring-0.1.0.1...
Preprocessing library packedstring-0.1.0.1...
[1 of 1] Compiling Data.PackedString ( Data/PackedString.hs, dist/build/Data/PackedString.o )

Data/PackedString.hs:112:1:
    Illegal standalone deriving declaration
      Use -XStandaloneDeriving to enable this extension
Failed to install packedstring-0.1.0.1
cabal: Error: some packages failed to install:
packedstring-0.1.0.1 failed during the building phase. The exception was:
ExitFailure 1
riot-1.20080618 depends on packedstring-0.1.0.1 which failed to install.