Fix GHC 9.12 stackage projects

overlays/ghc-packages.nix

@@ -88,6 +88,9 @@ let
       ghc-internal = "libraries/ghc-internal";
     } // final.lib.optionalAttrs (builtins.compareVersions ghcVersion "9.10" >= 0) {
       ghc-toolchain = "utils/ghc-toolchain";
+    } // final.lib.optionalAttrs (builtins.compareVersions ghcVersion "9.12" >= 0) {
+      ghc-experimental = "libraries/ghc-experimental";
+      haddock-api = "utils/haddock/haddock-api";
     };
 
   # The nix produced by `cabalProject` differs slightly depending on

test/stack-simple/default.nix

@@ -5,13 +5,14 @@ with lib;
 let
   project = pkgs.haskell-nix.stackProject' {
     src = testSrc "stack-simple";
+    stackYaml = "stack-${compiler-nix-name}.yaml";
     inherit evalPackages;
   };
 
   packages = project.hsPkgs;
 
 in pkgs.recurseIntoAttrs {
-  meta.disabled = compiler-nix-name != "ghc984";
+  meta.disabled = !builtins.pathExists ./stack-${compiler-nix-name}.yaml;
   stack-simple-exe = (haskellLib.check packages.stack-simple.components.exes.stack-simple-exe) // {
       # Attributes used for debugging with nix repl
       inherit pkgSet packages;

test/stack-simple/stack-ghc9102.yaml

@@ -0,0 +1,69 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# resolver: ./custom-snapshot.yaml
+# resolver: https://example.com/snapshots/2018-01-01.yaml
+resolver: nightly-2025-07-14
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#  subdirs:
+#  - auto-update
+#  - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# using the same syntax as the packages field.
+# (e.g., acme-missiles-0.3)
+extra-deps:
+  # Work around http://hackage.haskell.org/package/transformers-0.5.5.0/transformers.cabal
+  # This is the version of transformers which ships with GHC-8.6.4
+  - transformers-0.5.6.2
+  # ghc-8.6.4 ships with process-1.6.5.0, not 1.6.3.0 as stackage claims. 1.6.3.0 isn't even compatible with
+  # base 4.12 that ghc ships.
+  - process-1.6.5.0
+# Override default flag values for local packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.9"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor

test/stack-simple/stack-ghc9122.yaml

@@ -0,0 +1,69 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# resolver: ./custom-snapshot.yaml
+# resolver: https://example.com/snapshots/2018-01-01.yaml
+resolver: nightly-2025-07-26
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#  subdirs:
+#  - auto-update
+#  - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# using the same syntax as the packages field.
+# (e.g., acme-missiles-0.3)
+extra-deps:
+  # Work around http://hackage.haskell.org/package/transformers-0.5.5.0/transformers.cabal
+  # This is the version of transformers which ships with GHC-8.6.4
+  - transformers-0.5.6.2
+  # ghc-8.6.4 ships with process-1.6.5.0, not 1.6.3.0 as stackage claims. 1.6.3.0 isn't even compatible with
+  # base 4.12 that ghc ships.
+  - process-1.6.5.0
+# Override default flag values for local packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.9"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor