Haddock documentation not linked into user index

Hi, I am using following script to wrap `cabal install` to avoid installing to public space. The building seemed fine. And the documents were installed into ".cabal/share/doc/x86_64-linux-ghc-7.6.3/". But they are not linked into ".cabal/share/doc/index.html". What else should I set?
`ghc-pkg init dist/db && cabal install --prefix=`pwd`/dist --datadir=$HOME/.cabal/share --package-db=`pwd`/dist/db`

Reproduce the report with the command in the issue, then inspect the generated files under .cabal/share/doc/x86_64-linux-ghc-7.6.3/ and .cabal/share/doc/index.html. Trace how cabal install handles Haddock output and the user index; done means installed documentation is linked from index.html for this local prefix and package database setup.

Written by the indexing model from the issue text.