`cabal new-haddock --haddock-for-hackage` claims to have created non-existent files

[sjakobi]

$ cabal get bytestring
$ cd bytestring-0.10.8.2
$ cabal new-configure -w ghc-8.4.1
$ cabal new-haddock --haddock-for-hackage
…
Documentation created:
/home/simon/src/bytestring/dist-newstyle/build/x86_64-linux/ghc-8.4.1/bytestring-0.10.9.0/doc/html/bytestring-0.10.9.0-docs/index.html,
/home/simon/src/bytestring/dist-newstyle/build/x86_64-linux/ghc-8.4.1/bytestring-0.10.9.0/doc/html/bytestring-0.10.9.0-docs/bytestring.txt
Documentation tarball created:
/home/simon/src/bytestring/dist-newstyle/bytestring-0.10.9.0-docs.tar.gz

But neither the index.html and bytestring.txt files nor the tarball exist.

[hvr]

see also https://github.com/haskell/cabal/issues/4412#issuecomment-301762546

[23Skidoo]

This is probably easy to fix, IIUC those files are not supposed to be created in --for-hackage mode in the first place.

[andreasabel]

Me too. cabal haddock --haddock-for-hackage prints it generated long/path/index.html, but this file does not exist. How can this happen? (Meaning: the code printing the report on what is being created should not make up filenames, but get a result vector which it prints out (selectively).)