id,summary,reporter,owner,description,type,status,priority,milestone,version,resolution,keywords,cc
180,Should not “succeed” if all installed libraries’ interface files are of the wrong version,wjt,,"I find myself with two versions of Haddock installed: the Debian-supplied 2.9.2 in /usr/bin, and a cabal-install-provided 2.4.2 in ~/.cabal/bin, which is first in my $PATH. (Presumably this was due to some package depending on a newer version of Haddock than Debian provided in the distant past.)

As a result, when I install any package (with 'documentation: True' in my ~/.cabal/config), I receive warnings as follows:

{{{
Installing executable(s) in /tmp/hmph/bin
Updating documentation index /tmp/hmph/share/doc/index.html
Warning: Cannot read /usr/lib/ghc-doc/haddock/Cabal-1.10.2.0/Cabal.haddock:
   ""Interface file is of wrong version: /usr/lib/ghc-doc/haddock/Cabal-1.10.2.0/Cabal.haddock""
Skipping this interface.
Warning: Cannot read /usr/lib/ghc-doc/haddock/hunit-1.2.2.3/HUnit.haddock:
   ""Interface file is of wrong version: /usr/lib/ghc-doc/haddock/hunit-1.2.2.3/HUnit.haddock""
Skipping this interface.
... and so on, for every installed library
}}}

Since all of my installed libraries' .haddock files are of the wrong version, it might be nice if haddock failed, rather than succeeding but writing an [http://willthompson.co.uk/misc/empty-docs/ empty documentation index].",enhancement,new,trivial,,2.4.2,,,