Use cabal 3.8

builder/comp-builder.nix

@@ -239,7 +239,7 @@ let
     (lib.concatMap (c: if c.isHaskell or false
       then builtins.attrValues (c.components.exes or {})
       else [c]) build-tools) ++
-    lib.optional (pkgconfig != []) buildPackages.pkgconfig;
+    lib.optional (pkgconfig != []) buildPackages.cabalPkgConfigWrapper;
 
   # Unfortunately, we need to wrap ghc commands for cabal builds to
   # work in the nix-shell. See ../doc/removing-with-package-wrapper.md.

builder/default.nix

@@ -17,7 +17,7 @@ let
     # in the native case, it would be the same in the cross case however
     # we *really* want to build the Setup.hs on the build machine and not
     # have the stdenv confuse it with the target/host env.
-    inherit (buildPackages) stdenv pkgconfig;
+    inherit (buildPackages) stdenv;
     inherit buildPackages;
     inherit haskellLib nonReinstallablePkgs makeSetupConfigFiles;
   };

builder/hspkg-builder.nix

@@ -53,7 +53,7 @@ let
       ||
         # These are the dependencies of `Cabal`
         !builtins.elem package.identifier.name
-          ["nix-tools" "alex" "happy" "hscolour" "Cabal" "bytestring" "aeson" "time"
+          ["nix-tools" "alex" "happy" "hscolour" "Cabal" "Cabal-syntax" "bytestring" "aeson" "time"
            "filepath" "base-compat-batteries" "base-compat" "unix" "directory" "transformers"
            "containers" "binary" "mtl" "text" "process" "parsec"];
 

builder/setup-builder.nix

@@ -1,4 +1,4 @@
-{ pkgs, stdenv, lib, buildPackages, haskellLib, ghc, nonReinstallablePkgs, hsPkgs, makeSetupConfigFiles, pkgconfig }@defaults:
+{ pkgs, stdenv, lib, buildPackages, haskellLib, ghc, nonReinstallablePkgs, hsPkgs, makeSetupConfigFiles }@defaults:
 
 let self =
 { component, package, name, src, enableDWARF ? false, flags ? {}, revision ? null, patches ? [], defaultSetupSrc
@@ -38,7 +38,7 @@ let
     (lib.concatMap (c: if c.isHaskell or false
       then builtins.attrValues (c.components.exes or {})
       else [c]) component.build-tools) ++
-    lib.optional (component.pkgconfig != []) pkgconfig;
+    lib.optional (component.pkgconfig != []) buildPackages.cabalPkgConfigWrapper;
 
   drv =
     stdenv.mkDerivation ({

changelog.md

@@ -1,6 +1,36 @@
 This file contains a summary of changes to Haskell.nix and `nix-tools`
 that will impact users.
 
+## Sep 6, 2022
+* A `pkgconfigSelector` must now be passed to cabal projects that have
+  `pkgconfig-depends`.  Use the pkg-config names.  For instance if the
+  project uses `gi-gtk` pass:
+  ```
+  pkgconfigSelector = p: [ p."gtk+-3.0" p."gobject-introspection-1.0" ];
+  ```
+  The dependencies of gtk will be included automatically.
+
+  Why?
+
+  Cabal 3.8 fixes a bug https://github.com/haskell/cabal/issues/6771
+  that haskell.nix relied on (probably wrongly), to create a plan
+  for a haskell project without knowing the pkg-config versions
+  available ahead of time.
+
+  This was probably a bad idea.
+
+  We could try to provide every pkg-config derivation in nixpkgs to
+  the derivation that generates the cabal plan. Unfortunately:
+  * That would introduce a massive dependency tree to the plan-nix
+    dervaition.
+  * Some of those packages may not build.
+
+  The `pkgconfigSelector` allows haskell.nix to filter out only the
+  packages we need from the available map (`lib/pkgconf-nixpkgs-map.nix`).
+
+  It should be thought of as the haskell.nix equivalent of installing
+  your pkg-config dependencies before running `cabal build`.
+
 ## Jul 27, 2022
 * Removed reliance on `builtins.currentSystem`.  It was used it to provide
   `pkgs.evalPackages` via an overlay that it used to run derivations

lib/call-cabal-project-to-nix.nix

@@ -66,6 +66,7 @@ in
                             # any plutus-apps input being used for a
                             # package.
 , evalPackages
+, pkgconfigSelector ? (_: [])
 , ...
 }@args:
 
@@ -167,6 +168,8 @@ let
 
   index-state-pinned = index-state != null || cabalProjectIndexState != null;
 
+  pkgconfPkgs = import ./pkgconf-nixpkgs-map.nix pkgs;
+
 in
   assert (if index-state-found == null
     then throw "No index state passed and none found in ${cabalProjectFileName}" else true);
@@ -329,14 +332,14 @@ let
   # when `checkMaterialization` is set.
   dummy-ghc-data =
     let
-      materialized = ../materialized/dummy-ghc + "/${ghc.targetPrefix}${ghc.name}-${pkgs.stdenv.buildPlatform.system}";
+      materialized = ../materialized/dummy-ghc + "/${ghc.targetPrefix}${ghc.name}-${pkgs.stdenv.buildPlatform.system}"
+        + pkgs.lib.optionalString (builtins.compareVersions ghc.version "8.10" < 0 && ghc.targetPrefix == "" && builtins.compareVersions pkgs.lib.version "22.05" < 0) "-old";
     in pkgs.haskell-nix.materialize ({
       sha256 = null;
       sha256Arg = "sha256";
       materialized = if __pathExists materialized
         then materialized
-        else __trace ("WARNING: No materialized dummy-ghc-data for "
-            + "${ghc.targetPrefix}${ghc.name}-${pkgs.stdenv.buildPlatform.system}.")
+        else __trace "WARNING: No materialized dummy-ghc-data.  mkdir ${toString materialized}"
           null;
       reasonNotSafe = null;
     } // pkgs.lib.optionalAttrs (checkMaterialization != null) {
@@ -463,7 +466,10 @@ let
   } // pkgs.lib.optionalAttrs (checkMaterialization != null) {
     inherit checkMaterialization;
   }) (evalPackages.runCommand (nameAndSuffix "plan-to-nix-pkgs") {
-    nativeBuildInputs = [ nix-tools dummy-ghc dummy-ghc-pkg cabal-install evalPackages.rsync evalPackages.gitMinimal ];
+    nativeBuildInputs = [ nix-tools dummy-ghc dummy-ghc-pkg cabal-install evalPackages.rsync evalPackages.gitMinimal evalPackages.pkgconfig ];
+    # We only need the `.dev` derivation (if there is one), since it will have
+    # the pkgconfig files needed by cabal.
+    buildInputs = map pkgs.lib.getDev (builtins.concatLists (pkgconfigSelector pkgconfPkgs));
     # Needed or stack-to-nix will die on unicode inputs
     LOCALE_ARCHIVE = pkgs.lib.optionalString (evalPackages.stdenv.buildPlatform.libc == "glibc") "${evalPackages.glibcLocales}/lib/locale/locale-archive";
     LANG = "en_US.UTF-8";

lib/ghcjs-project.nix

@@ -39,7 +39,7 @@
   if (builtins.compareVersions ghcjsVersion "8.10.0.0" >= 0)
   then pkgs.haskell-nix.tool compiler-nix-name "cabal" {
     index-state = pkgs.haskell-nix.internalHackageIndexState;
-    version = "3.6.2.0";
+    version = "3.8.1.0";
     materialized = ../materialized/ghcjs/cabal + "/${compiler-nix-name}";
   }
   else pkgs.haskell-nix.tool compiler-nix-name "cabal" {
@@ -48,7 +48,7 @@
     # Cabal 3.2.1.0 no longer supports he mix of `cabal-version`,
     # lack of `custom-setup` and `v1-install` used by ghcjs boot.
     cabalProjectLocal = ''
-      constraints: Cabal <3.2.1.0
+      constraints: Cabal <3.2.1.0, Cabal-syntax <0
     '';
     materialized = ../materialized/ghcjs/cabal + "/${compiler-nix-name}";
   }