Update the non-toolchain examples to bzlmod

.github/workflows/workflow.yaml

@@ -102,12 +102,6 @@ jobs:
             read -a ${1} <<< $(echo ${!p//$2})
           }
 
-          pushd examples/cc-template
-          echo
-          echo "::group::Running $(head -n1 README.md) with Nix, WORKSPACE"
-          nix develop --command bazel run --noenable_bzlmod //src:hello-world
-          popd
-
           pushd examples/cc-template
           echo
           echo "::group::Running $(head -n1 README.md) with Nix, bzlmod"
@@ -144,20 +138,16 @@ jobs:
           popd
 
       - name: Build bazel-nix-python-container with Nix
-        uses: tweag/run-nix-shell@v0
         if: ${{ runner.os == 'Linux' }}
-        with:
-          pure: false
-          working-directory: examples/python-container
-          run: bazel build :hello_image
+        working-directory: examples/python-container
+        run: |
+          nix-shell --pure --run "bazel build :hello_image"
 
       - name: Run bazel-nix-flakes-example with Nix
-        uses: tweag/run-nix-shell@v0
         if: ${{ runner.os == 'Linux' }}
-        with:
-          pure: false
-          working-directory: examples/flakes
-          run: bazel run --crosstool_top=@nixpkgs_config_cc//:toolchain :hello
+        working-directory: examples/flakes
+        run: |
+          nix-shell --pure --run "bazel run :hello"
 
   all_ci_tests:
     runs-on: ubuntu-latest

examples/cc-template/MODULE.bazel

@@ -1,12 +1,20 @@
 module(name = "rules_nixpkgs_guide")
 
 bazel_dep(name = "rules_nixpkgs_core")
-# Remove to use rules_nixpkgs_core from the BCR
 local_path_override(
     module_name = "rules_nixpkgs_core",
     path = "../../core",
 )
 
+bazel_dep(name = "rules_nixpkgs_cc")
+local_path_override(
+    module_name = "rules_nixpkgs_cc",
+    path = "../../toolchains/cc",
+)
+
+bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "rules_cc", version = "0.2.14")
+
 nix_repo = use_extension("@rules_nixpkgs_core//extensions:repository.bzl", "nix_repo")
 nix_repo.file(
     name = "nixpkgs",
@@ -15,22 +23,13 @@ nix_repo.file(
 )
 use_repo(nix_repo, "nixpkgs")
 
-bazel_dep(name = "rules_nixpkgs_cc")
-# Replace by archive_override to download a rules_nixpkgs_cc revision.
-# (rules_nixpkgs_cc is not available on the BCR, yet.)
 #
-#     archive_override(
-#         module_name = "rules_nixpkgs_cc",
-#         urls = ["https://github.com/tweag/rules_nixpkgs/releases/download/v0.11.1/rules_nixpkgs-0.11.1.tar.gz"],
-#         integrity = "sha256-KlVTSNf4WT/KK/P8bOU8XWKSnegbbCkuI/FsVXwK5Fo=",
-#         strip_prefix = "rules_nixpkgs-0.11.1/toolchains/cc",
-#     )
-local_path_override(
-    module_name = "rules_nixpkgs_cc",
-    path = "../../toolchains/cc",
-)
+# Toolchains
+#
+
+cc_configure = use_extension("//:extension.bzl", "cc_configure")
+use_repo(cc_configure, "nixpkgs_config_cc")
+use_repo(cc_configure, "nixpkgs_config_cc_toolchains")
+use_repo(cc_configure, "nixpkgs_config_cc_info")
 
-# TODO remove transitive rules_nixpkgs_cc dependencies.
-#   Once there is a module extension for the cc toolchain.
-bazel_dep(name = "bazel_skylib", version = "1.7.1")
-bazel_dep(name = "rules_cc", version = "0.0.9")
+register_toolchains("@nixpkgs_config_cc_toolchains//:all")

examples/cc-template/extension.bzl

@@ -0,0 +1,12 @@
+load("@rules_nixpkgs_cc//:cc.bzl", "nixpkgs_cc_configure")
+
+def _cc_configure_impl(module_ctx):
+    nixpkgs_cc_configure(
+        name = "nixpkgs_config_cc",
+        repository = "@nixpkgs",
+        register = False,
+    )
+
+cc_configure = module_extension(
+    implementation = _cc_configure_impl,
+)

examples/flakes/.bazelrc

@@ -1 +1,4 @@
 import %workspace%/../../.bazelrc.remote-cache
+
+build --host_platform=@rules_nixpkgs_core//platforms:host
+build --crosstool_top=@nixpkgs_config_cc//:toolchain

examples/flakes/MODULE.bazel

@@ -0,0 +1,35 @@
+module(name = "rules_nixpkgs_flakes_example")
+
+bazel_dep(name = "rules_nixpkgs_core")
+local_path_override(
+    module_name = "rules_nixpkgs_core",
+    path = "../../core",
+)
+
+bazel_dep(name = "rules_nixpkgs_cc")
+local_path_override(
+    module_name = "rules_nixpkgs_cc",
+    path = "../../toolchains/cc",
+)
+
+bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "rules_cc", version = "0.2.14")
+
+nix_repo = use_extension("@rules_nixpkgs_core//extensions:repository.bzl", "nix_repo")
+nix_repo.flake(
+    name = "nixpkgs",
+    lock_file = "//:flake.lock",
+    file_deps = ["//:flake.lock"],
+)
+use_repo(nix_repo, "nixpkgs")
+
+#
+# Toolchains
+#
+
+cc_configure = use_extension("//:extension.bzl", "cc_configure")
+use_repo(cc_configure, "nixpkgs_config_cc")
+use_repo(cc_configure, "nixpkgs_config_cc_toolchains")
+use_repo(cc_configure, "nixpkgs_config_cc_info")
+
+register_toolchains("@nixpkgs_config_cc_toolchains//:all")

examples/flakes/README.md

@@ -9,8 +9,6 @@ The nix package manager should be installed with flakes support enabled.
 
 ## Running the example
 
-The local nixpkgs repository can be used by explicitly specifying the generated toolchain.
-
 ``bash
-nix-shell --run "bazel run --crosstool_top=@nixpkgs_config_cc//:toolchain :hello"
+nix-shell --run "bazel run :hello"
 ```

examples/flakes/extension.bzl

@@ -0,0 +1,13 @@
+load("@rules_nixpkgs_cc//:cc.bzl", "nixpkgs_cc_configure")
+
+def _cc_configure_impl(module_ctx):
+    nixpkgs_cc_configure(
+        name = "nixpkgs_config_cc",
+        repository = "@nixpkgs",
+        attribute_path = "clang_16",
+        register = False,
+    )
+
+cc_configure = module_extension(
+    implementation = _cc_configure_impl,
+)

examples/flakes/flake.nix

@@ -2,7 +2,7 @@
   description = "C++ environment using Nix flakes";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-22.11";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
     flake-compat = {
       url = "github:edolstra/flake-compat";
       flake = false;
@@ -19,7 +19,7 @@
       {
         devShells.default = with pkgs; mkShell {
           name = "flake-example-shell";
-          packages = [ gcc gnumake bazel_6 ];
+          packages = [ gcc nix bazel_7 ];
         };
       });
 }

examples/python-container/.bazeliskrc

@@ -0,0 +1 @@
+USE_BAZEL_VERSION=7.x