How to hide Prelude?

[adlaika]

After seeing the following error trying to stack build a project that relies on polysemy-conc (and thus on incipit-core)...

unix-time              > configure
unix-time              > [1 of 2] Compiling Main             ( /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/Setup.hs, /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/setup/Main.o )
unix-time              >
unix-time              > /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/Setup.hs:1:8: error:
unix-time              >     Ambiguous module name ‘Prelude’:
unix-time              >       it was found in multiple packages:
unix-time              >       base-4.15.1.0 incipit-base-0.2.0.0 incipit-core-0.2.0.0
unix-time              >   |
unix-time              > 1 | module Main (main) where
unix-time              >   |        ^^^^
Progress 1/15

--  While building package unix-time-0.4.7 (scroll up to its section to see the error) using:
      /Users/adlai/.stack/programs/aarch64-osx/ghc-9.0.2/bin/ghc-9.0.2 --make -odir /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/setup -hidir /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/setup -i -i. -package=Cabal-3.4.1.0 -clear-package-db -global-package-db -package-db=/Users/adlai/.stack/snapshots/aarch64-osx/4e2abd3a1f3c6ee84ca3952d068f82fc24a4e1b9a3ccaae9959e1791b6a5f81b/9.0.2/pkgdb /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/Setup.hs /Users/adlai/.stack/setup-exe-src/setup-shim-mPHDZzAJ.hs -main-is StackSetupShim.mainOverride -o /private/var/folders/5t/7vlbcgyd6_73wtq7gjx35g3r0000gn/T/stack-3ae17c9d728419f4/unix-time-0.4.7/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/setup/setup -threaded
    Process exited with code: ExitFailure 1

...I tried the README's suggestion in package.yaml's dependencies block:

- name: base 
    version: '>= 4.14.1.0'
    mixin:
      - hiding (Prelude)

However, I'm still getting the same error. Is there something I'm missing? Thanks!

[tek]

I've seen someone else have this exact problem, also happening during build of unix-time. I tried to reproduce with their test case but the issue didn't occur. It looks like Stack is adding the extra-depends of the main project to the dependencies of unix-time.

Have you tried wiping ~/.stack or ~/.cabal?

[tek]

oh and which stack version are you using?

[adlaika]

oh and which stack version are you using?

2.7.5

[tek]

https://github.com/qwbarch/ambiguous-prelude

this is the reproducer of the other reporter of this bug, can you verify it happens for you there as well?

[tek]

just tried again, stack 2.7.5, clean cache. built successfully

[adlaika]

https://github.com/qwbarch/ambiguous-prelude

this is the reproducer of the other reporter of this bug, can you verify it happens for you there as well?

I was able to build this project successfully (after accounting for a Mac M1 specific problem that I'm 99% sure is unrelated).

[adlaika]

Attempting with the same LTS as my project.

[tek]

huh!

@qwbarch was using a Debian VM, so it's definitely unrelated to MacOS

[tek]

do you have a repo I can try?

[adlaika]

I've seen someone else have this exact problem, also happening during build of unix-time. I tried to reproduce with their test case but the issue didn't occur. It looks like Stack is adding the extra-depends of the main project to the dependencies of unix-time.

Have you tried wiping ~/.stack or ~/.cabal?

Haven't tried this yet, but I did stack clean && stack purge at least once.

[adlaika]

do you have a repo I can try?

I'll try to get you a minimal example after lunch.

[adlaika]

Attempting with the same LTS as my project.

This worked as well.

[tek]

I found this: https://github.com/commercialhaskell/stack/issues/5414

[tek]

might be worth trying:

$ rm -rf ~/.stack/snapshots/...
$ rm -rf .stack-work
$ stack build unix-time
$ stack build

[tek]

:sweat_smile: Stack's hermeticity appears to be severely lacking, I guess :slightly_smiling_face:

[adlaika]

Yeah, looks like that worked--build is well past that point now. Had to do it again for network.

[tek]

oh wow. that's also the package that failed in the linked issue

[tek]

very curious, given that alternative preludes aren't exactly an exotic concept. wonder if Relude et al. are doing something to prevent that

[adlaika]

very curious, given that alternative preludes aren't exactly an exotic concept. wonder if Relude et al. are doing something to prevent that

we use classy-prelude, which exports ClassyPrelude instead.

[tek]

oh right

[adlaika]

So...now I'm getting:

➜ stack build
Building all executables for `nauvoo' once. After a successful build of all of them, only specified executables will be rebuilt.
nauvoo> build (lib + exe)
Preprocessing library for nauvoo-0.0.0.1..
Building library for nauvoo-0.0.0.1..
[ 15 of 198] Compiling Paths_nauvoo

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:41:53: error:
    Variable not in scope: return :: FilePath -> IO String
   |
41 | getBinDir = catchIO (getEnv "nauvoo_bindir") (\_ -> return bindir)
   |                                                     ^^^^^^

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:42:53: error:
    Variable not in scope: return :: FilePath -> IO String
   |
42 | getLibDir = catchIO (getEnv "nauvoo_libdir") (\_ -> return libdir)
   |                                                     ^^^^^^

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:43:59: error:
    Variable not in scope: return :: FilePath -> IO String
   |
43 | getDynLibDir = catchIO (getEnv "nauvoo_dynlibdir") (\_ -> return dynlibdir)
   |                                                           ^^^^^^

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:44:55: error:
    Variable not in scope: return :: FilePath -> IO String
   |
44 | getDataDir = catchIO (getEnv "nauvoo_datadir") (\_ -> return datadir)
   |                                                       ^^^^^^

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:45:61: error:
    Variable not in scope: return :: FilePath -> IO String
   |
45 | getLibexecDir = catchIO (getEnv "nauvoo_libexecdir") (\_ -> return libexecdir)
   |                                                             ^^^^^^

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:46:61: error:
    Variable not in scope: return :: FilePath -> IO String
   |
46 | getSysconfDir = catchIO (getEnv "nauvoo_sysconfdir") (\_ -> return sysconfdir)
   |                                                             ^^^^^^

/Users/adlai/gits/astro/nauvoo/.stack-work/dist/aarch64-osx/Cabal-3.4.1.0/build/autogen/Paths_nauvoo.hs:51:3: error:
    Variable not in scope: return :: [Char] -> IO FilePath
   |
51 |   return (dir ++ "/" ++ name)
   |   ^^^^^^

--  While building package nauvoo-0.0.0.1 (scroll up to its section to see the error) using:
      /Users/adlai/.stack/setup-exe-cache/aarch64-osx/Cabal-simple_mPHDZzAJ_3.4.1.0_ghc-9.0.2 --builddir=.stack-work/dist/aarch64-osx/Cabal-3.4.1.0 build lib:nauvoo exe:nauvoo exe:nauvoo-integration --ghc-options " -fdiagnostics-color=always"
    Process exited with code: ExitFailure 1

...which I assume is the result of not having some Prelude in scope somewhere?

[adlaika]

but perhaps is unrelated?

[tek]

are you using Incipit as your prelude explicitly, i.e. specifying hiding (Prelude) for base?

[tek]

I'm not suggesting you do that, but if so, you might want to disable the Paths_nauvoo module with

  when:
    condition: false
    generated-other-modules:
      - Paths_nauvoo

in your hpack file

[tek]

this is a more general issue, discussed frequently on the cabal issue tracker, like here: https://github.com/haskell/cabal/issues/7761

[tek]

oh right, you're using classy-prelude. that should apply for that as well, I think

[adlaika]

I'm not suggesting you do that, but if so, you might want to disable the Paths_nauvoo module with

  when:
    condition: false
    generated-other-modules:
      - Paths_nauvoo

in your hpack file

No luck with either this or the solution from #7761:

library paths-nauvoo
  default-language: Haskell2010
  build-depends: base
  autogen-modules: Paths_nauvoo
  exposed-modules: Paths_nauvoo
library
...
  build-depends:
    ...
    , paths-nauvoo
...

Is it necessary to wipe ~/.stack and ~/.cabal between every attempt?

[tek]

no, this problem should be local to your project. let's first establish the circumstances – did I understand correctly that you're using classy-prelude, with something like

dependencies:
  - name: base
    mixin: (hiding Prelude)
  - name: classy-prelude
    mixin: (ClassyPrelude as Prelude)

Also, nauvoo is the project you're working on, not a dep?

If so, return appears to be exported by ClassyPrelude, which suggests that there is another weird interaction with incipit caused by stack. If that's the case, I'd definitely have to reevaluate the utility of providing a convienence Prelude module here.

[tek]

still strange that this only surfaces for the Paths module though.

[tek]

btw my hack for hiding Paths has to be added to both the library and all executables and tests. you can verify that it works if there is no mention of Paths in the generated nauvoo.cabal

[adlaika]

Sorry, I wasn't clear--we don't use a mixin for classy-prelude. We just import ClassyPrelude where needed.

[tek]

ok, that should have the same effect

[adlaika]

And yes--nauvoo is our project.

[adlaika]

btw my hack for hiding Paths has to be added to both the library and all executables and tests. you can verify that it works if there is no mention of Paths in the generated nauvoo.cabal

I'll try this.

[tek]

oh, you import ClassyPrelude when needed? as in, you still use Prelude from base by default?

[adlaika]

As far as I can tell, there's no mention of Paths in our nauvoo.cabal. That makes sense, since I actually generated it via hpack with

dependencies:
...
  - paths-nauvoo

verbatim: |
  library paths-nauvoo
    default-language: Haskell2010
    build-depends: base
    autogen-modules: Paths_nauvoo
    exposed-modules: Paths_nauvoo

...then library, executable, and tests all depend on the top-level dependencies

[adlaika]

oh, you import ClassyPrelude when needed? as in, you still use Prelude from base by default?

No, we use NoImplicitPrelude.

[adlaika]

(thank you for your time and patience, btw! really appreciate it :) )

[tek]

I see. so the default-visible Prelude used by Paths should definitely be from base. In any case, this is pretty bad UX, I will release a new version of all the packages without an exported Prelude in incipit-*. Might take a few days though :)

[tek]

and thank you for the valuable feedback :smile:

[adlaika]

That's awesome! Once polysemy-conc uses the new version, that'll solve our problem :)

[tek]

I just noticed the file /home/tek/.ghc/x86_64-linux-9.0.2/environments/default, seems to be generated by stack and contains a few package ids. That might be the source of the contamination.

[adlaika]

hmm. my ~/.ghc/ folder is empty. Maybe because I use ghcup?

[tek]

might be!

[adlaika]

As far as I can tell, my ~/.ghcup doesn't contain any equivalent to /home/tek/.ghc/x86_64-linux-9.0.2/environments/default

[tek]

@adlaika FYI all the libs have been released!

[adlaika]

Wow, quick! You rock, thanks so much for all the help :)

[tek]

please yell if anything still behaves unexpectedly!

[adlaika]

Will do--I'm out of town this weekend, but I'll give it a shot on Monday.

On Sat, Jun 11, 2022, 11:50 AM Torsten Schmits @.***> wrote:

please yell if anything still behaves unexpectedly!

— Reply to this email directly, view it on GitHub https://github.com/tek/incipit/issues/1#issuecomment-1152980397, or unsubscribe https://github.com/notifications/unsubscribe-auth/ACB7APJAM6QWX66ZKSZNSOLVOTNV5ANCNFSM5YOVRTVQ . You are receiving this because you were mentioned.Message ID: @.***>