GHC 8.8.1 and cabal-install 3.0 not compatible with ghc-pkg

Unfortunately ghc 8.8.1 and cabal-install 3.0 are not compatible with ghc-pkg as documented in https://github.com/haskell/cabal/issues/6262#issuecomment-538850477. As Daniel Grober wrote there: I think this is expected behaviour, at least from the cabal side of things. Version 3.0.0.0 switched to using v2-build by default so installed libraries are now registered into the "default" package environment file in .ghc/*/environments/default as well as a package-db in .cabal/store/ghc-*/package.db which GHC doesn't know about by itself. AFAICS ghc-pkg simply doesn't have support for listing package environments which sort of kind of makes sense but also breaks this workflow. I think this should be reported as a GHC bug but I'm not sure it would even be a good idea to add pkg-env support to ghc-pkg. I thought this might be a ghc issue but since nobody else was complaining I assumed I must have done something wrong. Should I file a ghc bug ? Thanks George On Sat, Sep 7, 2019 at 6:20 PM George Colpitts wrote:

Thanks for everybody's responses. I figured out that the following

cabal-install users should note that cabal-install-3.0 or later is required for use with GHC 8.8.

means I should have cabal-install-3.0 before installing 8.8.1. Once I did that everything is fine.

Maybe configure should give an error if the user does not have cabal-install-3.0?

Thanks George

On Fri, Sep 6, 2019 at 1:48 PM Shayne Fletcher wrote:

...

I got there by doing, ``` cabal v2-install --installdir=~/.cabal/bin alex cabal v2-install --installdir=~/.cabal/bin happy ``` and things seemed to be going smoothly enough after that.

On Fri, Sep 6, 2019 at 12:08 PM Carter Schonwald < carter.schonwald@gmail.com> wrote:

...

V1 or v2 install?

On Mon, Sep 2, 2019 at 11:42 AM George Colpitts < george.colpitts@gmail.com> wrote:

...

https://www.haskell.org/ghc/blog/20190825-ghc-8.8.1-released.html says

cabal-install users should note that cabal-install-3.0 or later is required for use with GHC 8.8.

but this seems wrong or have I done something wrong?

$ cabal install cabal-install cabal install cabal-install ...

Resolving dependencies... cabal: Could not resolve dependencies: [__0] trying: cabal-install-3.0.0.0 (user goal) [__1] next goal: time (dependency of cabal-install) [__1] rejecting: time-1.9.3/installed-1.9... (conflict: cabal-install => base>=4.8 && <4.13, time => base==4.13.0.0/installed-4.1...) [__1] trying: time-1.9.3 [__2] next goal: stm (dependency of cabal-install) [__2] rejecting: stm-2.5.0.0/installed-2.5... (conflict: cabal-install => base>=4.8 && <4.13, stm => base==4.13.0.0/installed-4.1...) [__2] trying: stm-2.5.0.0 [__3] next goal: process (dependency of cabal-install) [__3] rejecting: process-1.6.5.1/installed-1.6... (conflict: cabal-install => base>=4.8 && <4.13, process => base==4.13.0.0/installed-4.1...) [__3] trying: process-1.6.5.1 [__4] next goal: pretty (dependency of cabal-install) [__4] rejecting: pretty-1.1.3.6/installed-1.1... (conflict: cabal-install => base>=4.8 && <4.13, pretty => base==4.13.0.0/installed-4.1...) [__4] trying: pretty-1.1.3.6 [__5] next goal: network (dependency of cabal-install) [__5] rejecting: network-3.1.0.1/installed-CeX... (conflict: cabal-install => base>=4.8 && <4.13, network => base==4.13.0.0/installed-4.1...) [__5] trying: network-3.1.0.1 [__6] trying: hackage-security-0.5.3.0 (dependency of cabal-install) [__7] next goal: template-haskell (dependency of hackage-security) [__7] rejecting: template-haskell-2.15.0.0/installed-2.1... (conflict: cabal-install => base>=4.8 && <4.13, template-haskell => base==4.13.0.0/installed-4.1...) [__7] rejecting: template-haskell-2.15.0.0, template-haskell-2.14.0.0, template-haskell-2.13.0.0, template-haskell-2.12.0.0, template-haskell-2.11.1.0, template-haskell-2.11.0.0, template-haskell-2.10.0.0, template-haskell-2.9.0.0, template-haskell-2.8.0.0, template-haskell-2.7.0.0, template-haskell-2.6.0.0, template-haskell-2.5.0.0, template-haskell-2.4.0.1, template-haskell-2.4.0.0, template-haskell-2.3.0.1, template-haskell-2.3.0.0, template-haskell-2.2.0.0 (constraint from non-upgradeable package requires installed instance) [__7] fail (backjumping, conflict set: cabal-install, hackage-security, template-haskell) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: base, cabal-install, directory, template-haskell, process, time, network, pretty, hackage-security, deepseq, HTTP, stm, cabal-install:lib

On Mon, Aug 26, 2019 at 6:25 AM Ben Gamari wrote:

...

Hello everyone,

The GHC team is pleased to announce the release candidate for GHC 8.8.1. The source distribution, binary distributions, and documentation are available at

https://downloads.haskell.org/ghc/8.8.1

This release is the culmination of over 3000 commits by over one hundred contributors and has several new features and numerous bug fixes relative to GHC 8.6:

* Visible kind applications are now supported (GHC Proposal #15)

* Profiling now works correctly on 64-bit Windows (although still may be problematic on 32-bit Windows due to platform limitations; see #15934)

* A new code layout algorithm for amd64's native code generator significantly improving the runtime performance of some kernels

* The introduction of a late lambda-lifting pass which may reduce allocations significantly for some programs.

* Further work on Trees That Grow, enabling improved code re-use of the Haskell AST in tooling

* Users can write `forall` in more contexts (GHC Proposal #7)

* The pattern-match checker is now more precise in the presence of strict fields with uninhabited types.

* A comprehensive audit of GHC's memory ordering barriers has been performed, resulting in a number of fixes that should significantly improve the reliability of programs on architectures with weakly-ordered memory models (e.g. PowerPC, many ARM and AArch64 implementations).

* A long-standing linker limitation rendering GHCi unusable with projects with cyclic symbol dependencies has been fixed (#13786)

* Further work on the Hadrian build system

* Countless miscellaneous bug-fixes

Unfortunately, due to a build issue (#17108) found late in the release process i386 Windows builds are currently unavailable. These will be provided in the coming weeks.

As always, if anything looks amiss do let us know.

Happy compiling!

Cheers,

- Ben

[1] https://downloads.haskell.org/ghc/8.8.1/docs/html/users_guide/8.8.1-notes.ht... _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users

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