Hi! I ran into the same problem.
Apparently, we need cabal-install 2.0, which has not been released yet. A preliminary solution is to use the development version from the 2.0 branch. Binary packages can be found at http://ppa.launchpad.net/hvr/ghc/ubuntu/pool/main/c/cabal-install-2.0/ , for example. It is possible to extract the cabal-install executable from these packages, so that it can be installed without using some Linux distribution package manager. All the best, Wolfgang Am Mittwoch, den 26.07.2017, 18:45 -0700 schrieb Evan Laforge: > This seems like a silly question, but how can we install cabal-install > now? The latest hackage version 1.24.0.2 has Cabal (>=1.24.2 && > <1.25), but it looks like ghc Cabal is now at 2.*. > > I ran into this because if I get: > > % cabal install --only-dependencies > Resolving dependencies... > cabal: internal error when reading package index: failed to parse > .cabal > fileThe package index or index cache is probably corrupt. Running > cabal update > might fix it. > > It seems to be triggered by having 'ekg' in the deps list, since if I > take it out then I get some other errors about packages not liking the > new base, which is true. 'ekg' also doesn't like the new base, but > "internal error" is not the clearest way to express that :) > > It's frustrating that cabal-install still doesn't report the parse > error, even though the parse function returns one. It just ignores > the ParseFailed case. I was going to try fixing it and send a pull > request when I ran into the Cabal 2.* problem. > > On Wed, Jul 26, 2017 at 7:15 AM, Ben Gamari <b...@smart-cactus.org> > wrote: > > > > Wolfgang Jeltsch <wolfgang...@jeltsch.info> writes: > > > > > > > > Am Samstag, den 22.07.2017, 23:03 -0400 schrieb Ben Gamari: > > > > > > > > In addition, there are a number of new features, > > > > > > > > * A new, more type-safe type reflection mechanism > > > > > > > > * The long-awaited Backpack module system > > > > > > > > * Deriving strategies to disambiguate between GHC's various > > > > instance > > > > deriving mechanisms > > > > > > > > * Unboxed sum types, for efficient unpacked representation of > > > > sum > > > > data types > > > > > > > > * Compact regions, allowing better control over garbage > > > > collection > > > > in the presence of large heaps containing many long-lived > > > > objects. > > > > > > > > * Colorful messages and caret diagnostics for more legible > > > > errors > > > > > > > > A more thorough list of the changes in this release can be found > > > > in > > > > the release notes, > > > > > > > > https://haskell.org/ghc/docs/8.2.1/docs/html/users_guide/8.2.1 > > > > -notes.html > > > It seems that the release notes mention the new type reflection > > > mechanism und colorful messages only in the “Highlights” section, > > > not in > > > the “Full details” section, and that they do not mention the > > > Backpack > > > module system and unboxed sums at all. > > > > > Yes, indeed these were oversights. They are fixed in the ghc-8.2 > > branch > > and I will try to push newly generated documentation shortly. > > > > Cheers, > > > > - Ben > > > > _______________________________________________ > > Glasgow-haskell-users mailing list > > glasgow-haskell-us...@haskell.org > > http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-use > > rs > > _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs