Remove other references to BAZEL_USE_CPP_ONLY_TOOLCHAIN.

.bcr/rules_haskell/presubmit.yml

@@ -11,8 +11,6 @@ tasks:
   verify_targets:
     name: Verify build targets
     platform: ${{ platform }}
-    environment:
-      BAZEL_USE_CPP_ONLY_TOOLCHAIN: '1'
     shell_commands:
     - |
       if apt --version >/dev/null 2>/dev/null; then
@@ -22,7 +20,6 @@ tasks:
     batch_commands:
     # enforce certificate update
     - 'powershell -Command "Invoke-WebRequest -Uri https://hackage.haskell.org/root.json -OutFile out.json"'
-    - set BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
     build_flags:
       - '--incompatible_enable_cc_toolchain_resolution'
     build_targets:

.github/workflows/patch-test.yaml

@@ -72,7 +72,6 @@ jobs:
         shell: bash
         run: |
           export PATH=$HOME/bazel:$PATH
-          [[ ${{ runner.os }} == macOS ]] && export BAZEL_USE_CPP_ONLY_TOOLCHAIN=1
           export GHC_VERSION=${{ matrix.ghc-version }}
           cd rules_haskell_tests
           ./tests/run-start-script.sh --use-bindists

README.md

@@ -76,9 +76,6 @@ If you are on NixOS, this is the only way to set up your project,
 because the GHC toolchain provisioned through binary distributions
 cannot be executed on NixOS.
 
-If you are on macOS, you will have to set the environment variable
-`BAZEL_USE_CPP_ONLY_TOOLCHAIN = 1`, so that Bazel picks the correct C compiler.
-
 [bazel-cli-commands]: https://docs.bazel.build/versions/master/command-line-reference.html#commands
 [nixpkgs]: https://nixos.org/nixpkgs/
 
@@ -227,14 +224,6 @@ en_US.utf8
 POSIX
 ```
 
-### MacOS: Error: DEVELOPER_DIR not set.
-
-Make sure to set the following environment variable:
-```
-export BAZEL_USE_CPP_ONLY_TOOLCHAIN=1
-```
-This ensures that Bazel picks the correct C compiler.
-
 ### Windows: Incorrect `cc_toolchain` used
 
 If you're using Windows, bazel might use a different `cc_toolchain`

rules_haskell_tests/shell.nix

@@ -2,11 +2,6 @@
 
 with pkgs;
 mkShell {
-  # XXX: hack for macosX, this flags disable bazel usage of xcode
-  # Note: this is set even for linux so any regression introduced by this flag
-  # will be catched earlier
-  # See: https://github.com/bazelbuild/bazel/issues/4231
-  BAZEL_USE_CPP_ONLY_TOOLCHAIN = 1;
   TMPDIR = "/tmp";
 
   GHC_VERSION = ghcVersion;

rules_haskell_tests/tests/integration_testing/rules_haskell_integration_test.bzl

@@ -1,4 +1,4 @@
-load(":haskell_bazel_integration_test.bzl", "haskell_bazel_integration_test")
+load("@os_info//:os_info.bzl", "is_nix_shell", "is_windows")
 load(
     "@rules_bazel_integration_test//bazel_integration_test:defs.bzl",
     "integration_test_utils",
@@ -9,7 +9,7 @@ load(
     "SUPPORTED_NIXPKGS_BAZEL_PACKAGES",
 )
 load("//tests/integration_testing:dependencies.bzl", "nixpkgs_bazel_label")
-load("@os_info//:os_info.bzl", "is_nix_shell", "is_windows")
+load(":haskell_bazel_integration_test.bzl", "haskell_bazel_integration_test")
 
 def rules_haskell_integration_test(
         name,
@@ -43,7 +43,6 @@ def rules_haskell_integration_test(
                 "//tests:nix": [],
                 "//conditions:default": ["@platforms//:incompatible"],
             }),
-            additional_env_inherit = ["BAZEL_USE_CPP_ONLY_TOOLCHAIN"],
             **kwargs
         )
     elif not is_windows:
@@ -58,6 +57,5 @@ def rules_haskell_integration_test(
                 "//tests:nix": ["@platforms//:incompatible"],
                 "//conditions:default": [],
             }),
-            additional_env_inherit = ["BAZEL_USE_CPP_ONLY_TOOLCHAIN"],
             **kwargs
         )

shell.nix

@@ -9,11 +9,6 @@ let
     writeScriptBin "security" ''exec /usr/bin/security "$@"'';
 in
 mkShell {
-  # XXX: hack for macosX, this flags disable bazel usage of xcode
-  # Note: this is set even for linux so any regression introduced by this flag
-  # will be catched earlier
-  # See: https://github.com/bazelbuild/bazel/issues/4231
-  BAZEL_USE_CPP_ONLY_TOOLCHAIN = 1;
   TMPDIR = "/tmp";
 
   GHC_VERSION = ghcVersion;