WIP: Switch to ghc (js) 9.12 via nixpkgs

[maralorn]

This does probably drop Android and iOS support, otherwise it works on examples projects.

[arthurl]

Hi, is reflex-dom compiling on your branch? I used the work-on script on a sample project, and got this error:

error:
       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating derivation 'ghc-shell-for-reflex-template-0.1'
         whose name attribute is located at /nix/store/7a31bwdzpywkr8rw5cspqcw5wd0fxr0d-source/pkgs/stdenv/generic/make-derivation.nix:439:13

       … while evaluating attribute 'NIX_GHC' of derivation 'ghc-shell-for-reflex-template-0.1'
         at /nix/store/7a31bwdzpywkr8rw5cspqcw5wd0fxr0d-source/pkgs/development/haskell-modules/generic-builder.nix:999:13:
          998|             ) "${buildPackages.glibcLocales}/lib/locale/locale-archive";
          999|             "NIX_${ghcCommandCaps}" = "${ghcEnv}/bin/${ghcCommand}";
             |             ^
         1000|             "NIX_${ghcCommandCaps}PKG" = "${ghcEnv}/bin/${ghcCommand}-pkg";

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: attribute 'sharedLibrary' missing
       at /nix/store/7a31bwdzpywkr8rw5cspqcw5wd0fxr0d-source/pkgs/development/libraries/gobject-introspection/default.nix:174:33:
          173|   postCheck = ''
          174|     rm $out/lib/libregress-1.0${stdenv.targetPlatform.extensions.sharedLibrary}
             |                                 ^
          175|   '';

Looking at the full trace suggest that reflex-dom is the problem:

error:
       [...]
       … while evaluating derivation 'ghc-shell-for-reflex-template-0.1'
       [...]
       … while evaluating derivation 'javascript-unknown-ghcjs-ghc-native-bignum-9.12.2-with-packages'
       [...]
       … while evaluating derivation 'reflex-dom-0.6.3.4'
       [...]
       … while evaluating derivation 'jsaddle-webkit2gtk-0.9.9.3'
       [...]
       … while evaluating derivation 'gi-gio-2.0.37'
       [...]
       … while evaluating derivation 'gi-glib-2.0.30'
       [...]
       … while evaluating derivation 'haskell-gi-0.26.15'
       [...]
       … while evaluating derivation 'gobject-introspection-wrapped-1.82.0'
       [...]
       … while evaluating derivation 'gobject-introspection-1.82.0'
       [...]

(I'm new to reflex, so maybe I'm just doing something stupid.)

[maralorn]

Hey. Yes, reflex-dom compiles on my branch. However I haven’t tried the work-on script and it might need adapting.

[arthurl]

Hey. Yes, reflex-dom compiles on my branch. However I haven’t tried the work-on script and it might need adapting.

Just to confirm, is that with GHCJS?

[arthurl]

It probably doesn’t have anything to do with the work-on script; I tried the nix project setup as described here (https://github.com/reflex-frp/reflex-platform/blob/develop/docs/project-development.rst), and reflex / reflex-dom compiles just fine with GHC, but not GHCJS, yielding the same error as above.

[maralorn]

Yes I have built and executed a whole reflex-dom project with the js backend.

Your trace suggests that nix is trying to build libraries which should only be built for ghc native not for the js target. Which command are you running?

[arthurl]

Your trace suggests that nix is trying to build libraries which should only be built for ghc native not for the js target. Which command are you running?

I’ve made a minimal reflex project template (which is quite literally just this official guide) here: https://github.com/arthurl/reflex-project-template

If you clone the repository and run nix-shell default.nix -A shells.ghcjs, you should be able to reproduce the error.

(On the other hand, nix-shell default.nix -A shells.ghc does work, and the subsequent cabal build all succeeds.)

Am I missing something obvious? To be clear, the above does work on the master branch of reflex-platform.

[alexfmpe]

Sounds like both things are the same error - the project shell setup uses the same thing as workOn under the hood.

reflex-platform/project/default.nix

Line 170 in 2e0d31b

workOnMulti {

I believe this all pre-dates shellFor which is probably what we want in the long run, assuming it works for cross or at least ghcjs.

[maralorn]

I never used -A shells.ghjs and am not sure what it is for. Maybe you can try -A ghcjs.frontend?

[arthurl]

I never used -A shells.ghjs and am not sure what it is for. Maybe you can try -A ghcjs.frontend?

Huh, to my sheer surprise, it works! (To be clear, nix-build -A ghcjs.frontend succeeds.)

nix-shell default.nix -A shells.ghcjs just gives you a shell with ghcjs and cabal, for development. I don’t know enough about reflex-platform to figure out why this fails, while directly building the entire project with nix succeeds (since nix obviously has to use ghcjs to build the project).

What do you use for your dev environment then? nix-build doesn’t give you incremental builds like cabal does, which sort of suck if you’re actively modifying and re-compiling the project.

[alexfmpe]

I never used -A shells.ghcjs and am not sure what it is for.

It used to be for doing incremental cabal builds with ghcjs (e.g. fixing imports), debug (peek at ghc-pkg), etc.

[arthurl]

Actually, nix-build -A ghcjs.frontend does not work either, though it is a different problem. As mentioned in my previous post, the build succeeds, but when I opened the file bin/frontend.jsexe/index.html, I get the following error in the dev console in chromium:

all.js:149170 Aborted('HEAP8' was not exported. add it to EXPORTED_RUNTIME_METHODS (see the Emscripten FAQ))
abort @ all.js:149170

all.js:149188 Uncaught (in promise) RuntimeError: Aborted('HEAP8' was not exported. add it to EXPORTED_RUNTIME_METHODS (see the Emscripten FAQ))
    at abort (all.js:149188:11)
    at Object.get (all.js:149013:9)
    at h$initEmscriptenHeap (all.js:13531:35)
    at Module.onRuntimeInitialized (all.js:150267:1)
    at doRun (all.js:150201:37)
    at run (all.js:150217:5)
    at removeRunDependency (all.js:149158:7)
    at receiveInstance (all.js:149299:5)
    at receiveInstantiationResult (all.js:149317:12)
    at createWasm (all.js:149343:19)

(The above issue does not appear on the master branch of reflex-platform.)

[maralorn]

Yes, that is an issue I am working on.

See obsidiansystems/obelisk@c0bbd8f for more and a workaround.

[arthurl]

See obsidiansystems/obelisk@c0bbd8f for more and a workaround.

That works, thanks!

[maralorn]

After inspecting the reflex-packages overlay I guess we will need to go through that more careful again to make sure that overlay expects all flags that r-p is exposing.