Unable to load package `apecs-physics-0.4.5'

[montetzouma]

I cloned the apecs project and tried to build it with stack, so that I can try the shmup example.
However, stack build came up with the following error.
Is this an actual issue or am I doing something wrong?
Thanks!

C:\apecs>stack build
Building all executables for `examples' once. After a successful build of all of them, only specified executables will be rebuilt.
examples> build (exe)
examples> Preprocessing executable 'constraints' for examples-0.1.0.0..
examples> Building executable 'constraints' for examples-0.1.0.0..
examples> [1 of 1] Compiling Main
examples> ghc.exe: unable to load package `apecs-physics-0.4.5'
examples> ghc.exe:  | C:\apecs\.stack-work\install\daa122fe\lib\x86_64-windows-ghc-8.6.5\apecs-physics-0.4.5-8viuxTPOf3sKmCxD9w6vQN\HSapecs-physics-0.4.5-8viuxTPOf3sKmCxD9w6vQN.o: unknown symbol `pthread_cond_wait'

--  While building package examples-0.1.0.0 (scroll up to its section to see the error) using:
      C:\sr\setup-exe-cache\x86_64-windows\Cabal-simple_Z6RU0evB_2.4.0.1_ghc-8.6.5.exe --builddir=.stack-work\dist\e626a42b build exe:constraints exe:helloworld exe:shmup exe:simple exe:tumbler --ghc-options " -fdiagnostics-color=always"
    Process exited with code: ExitFailure 1

[jonascarpay]

Judging from the error, it looks like it has trouble compiling the C dependencies of the physics engine. I have never compiled apecs-phsyics on Windows, and I'm not sure what's going on or how to go about fixing it.

Luckily for you, you don't need apecs-physics at all for the shmup example. You should be able to build just that executable with stack build examples:shmup, can you confirm if that works?

[montetzouma]

Thanks for helping. I tried stack build examples:shmup but it comes up with the same error message I'm afraid. It might be a general problem of apecs (on Windows?) as I tried building the following project and it generated the same error as well.
Unity Tutorial Project in Haskell with Apecs and SDL2

[jonascarpay]

Strange, maybe stack doesn't know not to build other dependencies when building just 1 executable. Does stack build examples:simple work? Does stack build apecs work?

[montetzouma]

• stack build apecs did not produce any message, good or bad. I believe it was already built in one of my previous attempts.
• stack build examples:simple produced the same error regarding apecs-physics.

[jonascarpay]

I think a temporary workaround could be to just delete all executables that rely on apecs-physics from examples.cabal. That is, delete all lines from 35 to the end of file, and try building the executables again.

[montetzouma]

I'm afraid it's the same error even after deleting the lines from examples.cabal.
I also tried creating a new stack project with only the code from shmup in its Main and listing as dependencies only apecs, apecs-gloss, linear and random but it came up with the same error.
Perhaps then the apecs library itself depends on apecs-physics? Or there is a way to manually install the C dependencies of apecs-physics (presumably Chipmunk?) to circumvent this error?

[jonascarpay]

Ohhhhhhhh I realize what it is now, I forgot that apecs-gloss depends on apecs-physics...

The options for fixing this are

1. fixing the windows build of apecs-physics,
2. splitting out the physics parts of apecs-gloss into a separate package, and
3. adding a build flag to apecs-gloss to build without the physics parts.

Option 1 is obviously nicest, but I don't have a windows dev environment to try and reproduce on. I'll have a think about whether I prefer 2 or 3.

Just to be sure though, can you make sure that you can build the gloss package on windows?

[dpwiz]

Strange. I've certainly built projects with apecs-gloss on windows with stack.

[montetzouma]

I can confirm that gloss builds fine on Windows.
@jonascarpay thanks for helping! Let me know if you decide to implement either 2 or 3 (although after @dpwiz 's comment the issue might be different?). I'm not experienced with these kind of things but I'm happy to help with implementing 1 if you decide to try that.

[jonascarpay]

@dpwiz Hmm, thanks for the input. When you built it, was that as a dependency, or from the apecs project folder? This project is still on LTS 13, so maybe it's just a GHC version issue.
@montetzouma, can you try building with --resolver=lts-18?

[montetzouma]

It gives the same error with stack build --resolver=lts-18.
Mind you, I had to add the following extra dependencies (suggested by stack) in stack.yaml otherwise the build was failing.

extra-deps:
  - directory-1.3.6.2@sha256:6e5f3e0adfe94483d5754d97d741b7d23a5e085d47176075b1955d4fa78f37aa,2811
  - time-1.10@sha256:536801b30aa2ce66da07cb19847827662650907efb2af4c8bef0a6276445075f,5738
  - process-1.6.13.2@sha256:9733aa8a27b3e6c0f08a87a5c7287b3b73302d396f68f5655f9990a641368e3e,2845
  - Cabal-3.2.1.0@sha256:8743076ec022296f9771d962000c9ca3a0fe02e68c37b992c63e382a675f791d,27482

[dpwiz]

I've tested my game and the latest lts-18 is broken*, while lts-18.5 builds and runs all right.

*Something to do with GHC internal packages.

[dpwiz]

This looks like it
commercialhaskell/stackage#6176

[montetzouma]

Unfortunately, both stack build --resolver=lts-18.5 and stack build examples:shmup --resolver=lts-18.5 fail with the same error as above for me.
@dpwiz maybe your game uses gloss or sdl instead of apecs-gloss?
I attach the full build log in case it is helpful.
build.log

[dpwiz]

Definitely apecs-gloss (:

You can try building it too, but I'd expect the result will be the same: https://gitlab.com/dpwiz/spacemar