Skip Cabal in setup_deps for GHC 9.6

Author: avdv

WORKSPACE

@@ -179,7 +179,7 @@ stack_snapshot(
         "proto-lens-runtime",
         "lens-family",
     ],
-    setup_deps = {
+    setup_deps = {} if GHC_VERSION and GHC_VERSION.startswith("9.6.") else {
         # See https://github.com/tweag/rules_haskell/issues/1871
         "HUnit": ["@Cabal//:Cabal"],
         "bifunctors": ["@Cabal//:Cabal"],

extensions/rules_haskell_dependencies.bzl

@@ -7,6 +7,20 @@ load("@bazel_tools//tools/build_defs/repo:utils.bzl", "maybe")
 load("@rules_haskell//tools:os_info.bzl", "os_info")
 load("@rules_haskell_ghc_version//:ghc_version.bzl", "GHC_VERSION")
 
+def _empty_repo_impl(rctx):
+    fail(rctx.attr.error_msg)
+
+_empty_repo = repository_rule(
+    implementation = _empty_repo_impl,
+    doc = """A dummy repository that can be loaded from the MODULE.bazel file but not fetched.""",
+    attrs = {
+        "error_msg": attr.string(
+            doc = "The error message displayed if the repository is fetched",
+            mandatory = True,
+        ),
+    },
+)
+
 def repositories(*, bzlmod):  # @unused
     rules_haskell_dependencies_bzlmod()
 
@@ -24,7 +38,12 @@ def repositories(*, bzlmod):  # @unused
 
     # TODO: Remove when tests are run with a ghc version containing Cabal >= 3.10
     # See https://github.com/tweag/rules_haskell/issues/1871
-    if GHC_VERSION and GHC_VERSION.startswith("9.4."):
+    if GHC_VERSION and GHC_VERSION.startswith("9.6."):
+        _empty_repo(
+            name = "Cabal",
+            error_msg = "When using GHC >= 9.6, do not depend on @Cabal, as https://github.com/tweag/rules_haskell/issues/1871 is fixed.",
+        )
+    elif GHC_VERSION and GHC_VERSION.startswith("9.4."):
         http_archive(
             name = "Cabal",
             build_file_content = """

rules_haskell_tests/WORKSPACE

@@ -273,27 +273,31 @@ stack_snapshot(
         "temporary",
     ],
     setup_deps = {
-        "polysemy": ["cabal-doctest"],
-        # See https://github.com/tweag/rules_haskell/issues/1871
-        "HUnit": ["@Cabal//:Cabal"],
-        "bifunctors": ["@Cabal//:Cabal"],
-        "c2hs": ["@Cabal//:Cabal"],
-        "call-stack": ["@Cabal//:Cabal"],
-        "doctest": ["@Cabal//:Cabal"],
-        "generic-deriving": ["@Cabal//:Cabal"],
-        "happy": ["@Cabal//:Cabal"],
-        "hspec": ["@Cabal//:Cabal"],
-        "hspec-core": ["@Cabal//:Cabal"],
-        "hspec-discover": ["@Cabal//:Cabal"],
-        "hspec-expectations": ["@Cabal//:Cabal"],
-        "mono-traversable": ["@Cabal//:Cabal"],
-        "proto-lens-protoc": ["@Cabal//:Cabal"],
-        "proto-lens-runtime": ["@Cabal//:Cabal"],
-        "quickcheck-io": ["@Cabal//:Cabal"],
-        "transformers-compat": ["@Cabal//:Cabal"],
-        "type-errors": ["@Cabal//:Cabal"],
-        "typed-process": ["@Cabal//:Cabal"],
-        "unliftio-core": ["@Cabal//:Cabal"],
+        name: deps
+        for name, deps in {
+            "polysemy": ["cabal-doctest"],
+            # See https://github.com/tweag/rules_haskell/issues/1871
+            "HUnit": ["@Cabal//:Cabal"],
+            "bifunctors": ["@Cabal//:Cabal"],
+            "c2hs": ["@Cabal//:Cabal"],
+            "call-stack": ["@Cabal//:Cabal"],
+            "doctest": ["@Cabal//:Cabal"],
+            "generic-deriving": ["@Cabal//:Cabal"],
+            "happy": ["@Cabal//:Cabal"],
+            "hspec": ["@Cabal//:Cabal"],
+            "hspec-core": ["@Cabal//:Cabal"],
+            "hspec-discover": ["@Cabal//:Cabal"],
+            "hspec-expectations": ["@Cabal//:Cabal"],
+            "mono-traversable": ["@Cabal//:Cabal"],
+            "proto-lens-protoc": ["@Cabal//:Cabal"],
+            "proto-lens-runtime": ["@Cabal//:Cabal"],
+            "quickcheck-io": ["@Cabal//:Cabal"],
+            "transformers-compat": ["@Cabal//:Cabal"],
+            "type-errors": ["@Cabal//:Cabal"],
+            "typed-process": ["@Cabal//:Cabal"],
+            "unliftio-core": ["@Cabal//:Cabal"],
+        }.items()
+        if [d for d in deps if d != "@Cabal//:Cabal"] or not GHC_VERSION or not GHC_VERSION.startswith("9.6.")
     },
     stack_snapshot_json = "//:stackage_snapshot{}.json".format(
         "_" + str(GHC_VERSION) if GHC_VERSION else "",

tools/repositories.bzl

@@ -29,7 +29,7 @@ def rules_haskell_worker_dependencies(**stack_kwargs):
                 "text",
                 "vector",
             ],
-            setup_deps = {
+            setup_deps = {} if GHC_VERSION and GHC_VERSION.startswith("9.6.") else {
                 "bifunctors": ["@Cabal//:Cabal"],
                 "proto-lens-runtime": ["@Cabal//:Cabal"],
                 "transformers-compat": ["@Cabal//:Cabal"],