Use horizon-platform and horizon-devtools at GHC 9.6.x

[locallycompact]

Proof of concept for using https://horizon-haskell.net/ instead of nixpkgs package set.

• Working proof of concept on Linux
• Working proof of concept on macOS
• Linux & macOS horizon cache -> Use in GitHub Actions

[srid]

Testing this on macOS:

Full log

``` ❯ nix develop --show-trace error: … while calling the 'derivationStrict' builtin

     at /derivation-internal.nix:9:12:

        8|
        9|   strict = derivationStrict drvAttrs;
         |            ^
       10|

   … while evaluating derivation 'haskell-template'
     whose name attribute is located at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:352:7

   … while evaluating attribute '__impureHostDeps' of derivation 'haskell-template'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:491:7:

      490|       __propagatedSandboxProfile = unique (computedPropagatedSandboxProfile ++ [ propagatedSandboxProfile ]);
      491|       __impureHostDeps = computedImpureHostDeps ++ computedPropagatedImpureHostDeps ++ __propagatedImpureHostDeps ++ __impureHostDeps ++ stdenv.__extraImpureHostDeps ++ [
         |       ^
      492|         "/dev/zero"

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:330:5:

      329|   computedImpureHostDeps =
      330|     unique (concatMap (input: input.__propagatedImpureHostDeps or [])
         |     ^
      331|       (stdenv.extraNativeBuildInputs

   … while calling 'foldl''

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:139:5:

      138|     # The list to fold
      139|     list:
         |     ^
      140|

   … while calling anonymous lambda

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:330:24:

      329|   computedImpureHostDeps =
      330|     unique (concatMap (input: input.__propagatedImpureHostDeps or [])
         |                        ^
      331|       (stdenv.extraNativeBuildInputs

   … while calling 'chooseDevOutputs'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/attrsets.nix:1146:5:

     1145|     # List of packages to pick `dev` outputs from
     1146|     drvs:
         |     ^
     1147|     builtins.map getDev drvs;

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:293:51:

      292|       (map (drv: drv.__spliced.buildBuild or drv) (checkDependencyList "depsBuildBuild" depsBuildBuild))
      293|       (map (drv: drv.__spliced.buildHost or drv) (checkDependencyList "nativeBuildInputs" nativeBuildInputs'))
         |                                                   ^
      294|       (map (drv: drv.__spliced.buildTarget or drv) (checkDependencyList "depsBuildTarget" depsBuildTarget))

   … while calling 'checkDependencyList''

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:265:43:

      264|   checkDependencyList = checkDependencyList' [];
      265|   checkDependencyList' = positions: name: deps: flip imap1 deps (index: dep:
         |                                           ^
      266|     if isDerivation dep || dep == null || builtins.isString dep || builtins.isPath dep then dep

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/stdenv/generic/make-derivation.nix:265:49:

      264|   checkDependencyList = checkDependencyList' [];
      265|   checkDependencyList' = positions: name: deps: flip imap1 deps (index: dep:
         |                                                 ^
      266|     if isDerivation dep || dep == null || builtins.isString dep || builtins.isPath dep then dep

   … while calling 'flip'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/trivial.nix:148:16:

      147|   */
      148|   flip = f: a: b: f b a;
         |                ^
      149|

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/trivial.nix:148:19:

      147|   */
      148|   flip = f: a: b: f b a;
         |                   ^
      149|

   … while calling 'imap1'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:165:14:

      164|   */
      165|   imap1 = f: list: genList (n: f (n + 1) (elemAt list n)) (length list);
         |              ^
      166|

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/build-support/mkshell/default.nix:41:36:

       40|   buildInputs = mergeInputs "buildInputs";
       41|   nativeBuildInputs = packages ++ (mergeInputs "nativeBuildInputs");
         |                                    ^
       42|   propagatedBuildInputs = mergeInputs "propagatedBuildInputs";

   … while calling 'mergeInputs'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/build-support/mkshell/default.nix:17:17:

       16| let
       17|   mergeInputs = name:
         |                 ^
       18|     (attrs.${name} or [ ]) ++

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/pkgs/build-support/mkshell/default.nix:23:36:

       22|     # this leaves actual dependencies of the derivations in `inputsFrom`, but never the derivations themselves
       23|     (lib.subtractLists inputsFrom (lib.flatten (lib.catAttrs name inputsFrom)));
         |                                    ^
       24|

   … while calling 'flatten'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:186:13:

      185|   */
      186|   flatten = x:
         |             ^
      187|     if isList x

   … while calling anonymous lambda

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:188:21:

      187|     if isList x
      188|     then concatMap (y: flatten y) x
         |                     ^
      189|     else [x];

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:188:24:

      187|     if isList x
      188|     then concatMap (y: flatten y) x
         |                        ^
      189|     else [x];

   … while calling 'flatten'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:186:13:

      185|   */
      186|   flatten = x:
         |             ^
      187|     if isList x

   … while calling anonymous lambda

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:188:21:

      187|     if isList x
      188|     then concatMap (y: flatten y) x
         |                     ^
      189|     else [x];

   … from call site

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:188:24:

      187|     if isList x
      188|     then concatMap (y: flatten y) x
         |                        ^
      189|     else [x];

   … while calling 'flatten'

     at /nix/store/52nwmx07625ygk61mhzp02f407w498rl-source/lib/lists.nix:186:13:

      185|   */
      186|   flatten = x:
         |             ^
      187|     if isList x

   … while calling 'getOutput'

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/lib/attrsets.nix:1083:23:

     1082|   */
     1083|   getOutput = output: pkg:
         |                       ^
     1084|     if ! pkg ? outputSpecified || ! pkg.outputSpecified

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/stdenv/generic/make-derivation.nix:289:13:

      288|       (map (drv: drv.__spliced.buildBuild or drv) (checkDependencyList "depsBuildBuild" depsBuildBuild))
      289|       (map (drv: drv.__spliced.buildHost or drv) (checkDependencyList "nativeBuildInputs" nativeBuildInputs'))
         |             ^
      290|       (map (drv: drv.__spliced.buildTarget or drv) (checkDependencyList "depsBuildTarget" depsBuildTarget))

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/lib/lists.nix:165:29:

      164|   */
      165|   imap1 = f: list: genList (n: f (n + 1) (elemAt list n)) (length list);
         |                             ^
      166|

   … from call site

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/lib/lists.nix:165:32:

      164|   */
      165|   imap1 = f: list: genList (n: f (n + 1) (elemAt list n)) (length list);
         |                                ^
      166|

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/stdenv/generic/make-derivation.nix:261:73:

      260|   checkDependencyList = checkDependencyList' [];
      261|   checkDependencyList' = positions: name: deps: flip imap1 deps (index: dep:
         |                                                                         ^
      262|     if isDerivation dep || dep == null || builtins.isString dep || builtins.isPath dep then dep

   … from call site

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/stdenv/generic/make-derivation.nix:262:8:

      261|   checkDependencyList' = positions: name: deps: flip imap1 deps (index: dep:
      262|     if isDerivation dep || dep == null || builtins.isString dep || builtins.isPath dep then dep
         |        ^
      263|     else if isList dep then checkDependencyList' ([index] ++ positions) name dep

   … while calling 'isDerivation'

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/lib/attrsets.nix:780:5:

      779|     # Value to check.
      780|     value: value.type or null == "derivation";
         |     ^
      781|

   … from call site

     at /nix/store/lrmxkfadhlcrakza60w0mc8sc327a5qg-source/pkgs/development/haskell-modules/make-package-set.nix:94:56:

       93|       # Converts a returned function to a functor attribute set if necessary
       94|       ensureAttrs = v: if builtins.isFunction v then { __functor = _: v; } else v;
         |                                                        ^
       95|

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/with-packages-wrapper.nix:19:1:

       18| #   (hpkgs: [ hpkgs.mtl hpkgs.lens ])
       19| selectPackages:
         | ^
       20|

   … from call site

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/with-packages-wrapper.nix:69:62:

       68|                       (pkg: [ pkg ] ++ lib.optionals installDocumentation [ (lib.getOutput "doc" pkg) ])
       69|                       (lib.filter (x: x ? isHaskellLibrary) (lib.closePropagation packages))
         |                                                              ^
       70|                   );

   … while calling 'closePropagationFast'

     at /nix/store/lrmxkfadhlcrakza60w0mc8sc327a5qg-source/lib/deprecated.nix:168:26:

      167|   # See https://github.com/NixOS/nixpkgs/pull/194391 for details.
      168|   closePropagationFast = list:
         |                          ^
      169|     builtins.map (x: x.val) (builtins.genericClosure {

   … from call site

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/with-packages-wrapper.nix:45:19:

       44|
       45|   packages      = selectPackages haskellPackages
         |                   ^
       46|                   ++ lib.optional withHoogle (hoogleWithPackages selectPackages);

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/generic-builder.nix:747:32:

      746|
      747|         ghcEnv = withPackages (_:
         |                                ^
      748|           otherBuildInputsHaskell ++

   … while calling 'zipperCombinedPkgs'

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/make-package-set.nix:478:30:

      477|         # assuming new-style commands.
      478|         zipperCombinedPkgs = vals:
         |                              ^
      479|           pkgs.lib.concatMap

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/make-package-set.nix:480:14:

      479|           pkgs.lib.concatMap
      480|             (drvList: pkgs.lib.filter isNotSelected drvList)
         |              ^
      481|             vals;

   … while calling 'isNotSelected'

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/make-package-set.nix:459:25:

      458|         #   => true
      459|         isNotSelected = input: pkgs.lib.all (p: input.outPath or null != p.outPath) selected;
         |                         ^
      460|

   … while calling anonymous lambda

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/development/haskell-modules/make-package-set.nix:459:46:

      458|         #   => true
      459|         isNotSelected = input: pkgs.lib.all (p: input.outPath or null != p.outPath) selected;
         |                                              ^
      460|

   … while evaluating derivation 'aeson-2.2.1.0'
     whose name attribute is located at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/stdenv/generic/make-derivation.nix:348:7

   … while evaluating attribute 'depsBuildBuild' of derivation 'aeson-2.2.1.0'

     at /nix/store/vqljs1ixabpdbfmq3llnlkj5dac1hq4c-source/pkgs/stdenv/generic/make-derivation.nix:391:7:

      390|
      391|       depsBuildBuild              = elemAt (elemAt dependencies 0) 0;
         |       ^
      392|       nativeBuildInputs           = elemAt (elemAt dependencies 0) 1;

   … while evaluating derivation 'ghc-9.8.1'
     whose name attribute is located at /nix/store/cjvwy2rr87ir1nb6wvs9n6lvbnzlqrdg-source/pkgs/stdenv/generic/make-derivation.nix:348:7

   … while evaluating attribute 'preConfigure' of derivation 'ghc-9.8.1'

     at /nix/store/cjvwy2rr87ir1nb6wvs9n6lvbnzlqrdg-source/pkgs/development/compilers/ghc/common-hadrian.nix:284:3:

      283|   # TODO(@sternenseemann): investigate coreutils dependencies and pass absolute paths
      284|   preConfigure = ''
         |   ^
      285|     for env in $(env | grep '^TARGET_' | sed -E 's|\+?=.*||'); do

   … from call site

     at /nix/store/cjvwy2rr87ir1nb6wvs9n6lvbnzlqrdg-source/pkgs/development/compilers/ghc/common-hadrian.nix:314:8:

      313|     export NIX_LDFLAGS+=" -rpath $out/lib/ghc-${version}"
      314|   '' + lib.optionalString stdenv.isDarwin ''
         |        ^
      315|     export NIX_LDFLAGS+=" -no_dtrace_dof"

   … while calling 'optionalString'

     at /nix/store/cjvwy2rr87ir1nb6wvs9n6lvbnzlqrdg-source/lib/strings.nix:257:5:

      256|     # String to return if condition is true
      257|     string: if cond then string else "";
         |     ^
      258|

   error: cannot coerce null to a string

</summary>

[locallycompact]

How is that null? It's

  '' + lib.optionalString stdenv.isDarwin ''
    export NIX_LDFLAGS+=" -no_dtrace_dof"

    # GHC tries the host xattr /usr/bin/xattr by default which fails since it expects python to be 2.7
    export XATTR=${lib.getBin xattr}/bin/xattr
  ''

[locallycompact]

Actually can you check that's correct?

[locallycompact]

The source to build ghc is here: https://gitlab.horizon-haskell.net/ghc/horizon-ghc

[srid]

xattr is set to null in buildGhc.nix?

[srid]

Actually yes, that's a strange error that optionalString is getting null as 2nd argument.

[locallycompact]

What should xattr be set to?

[srid]

This works great. Instead of merging this in this repo, I want to upstream this module somewhere and document it in https://community.flake.parts/haskell-flake