Why is --gen-script creating failing scripts?

[Marc Weber]

I've been using the recent cabal from ghc-6.7.20070814

register.sh 
[...]
haddock-html: /pr/store/5wivrfz8pmc7hpwqgxgz44i4ihf1ka09-ghc67_filepath-1.0/nix-support/share/filepath-1.0/doc/html/filepath' | /pr/store/khvbwb3whj1c15pg7jrh7w4v2vndr8i7-ghc-6.7.20070814/bin/ghc-pkg update dist/installed-pkg-config -

marc at localhost /tmp/nix-10368-0/filepath-1.0 $ ghc-pkg list
/pr/store/khvbwb3whj1c15pg7jrh7w4v2vndr8i7-ghc-6.7.20070814/lib/ghc-6.7.20070814/package.conf:
    Cabal-1.1.7, [...]

Please use  either echo and add - or pass the pkg-conf
dist/installed-pkg-config ..

or did I mess something up?

If you like I can start debugging the issue and read the source.. But
propably you know what has been changed ?

Marc