test(e2e): move the pycross suites into an isolated e2e/crossbuild workspace

.github/workflows/ci-workflows.yaml

@@ -76,6 +76,7 @@ jobs:
                 workspace:
                 - { path: ".", slug: "root", runner: "ubuntu-latest" }
                 - { path: "e2e/cases", slug: "e2e", runner: "ubuntu-22.04-32core" }
+                - { path: "e2e/crossbuild", slug: "e2e-crossbuild", runner: "ubuntu-22.04-32core" }
                 - { path: "e2e/interpreter-runtime-metadata", slug: "e2e-interpreter-runtime-metadata", runner: "ubuntu-latest" }
                 - { path: "e2e/interpreter-toolchain-settings", slug: "e2e-interpreter-toolchain-settings", runner: "ubuntu-latest" }
                 - { path: "e2e/interpreter-input-validation", slug: "e2e-interpreter-input-validation", runner: "ubuntu-latest" }
@@ -129,6 +130,7 @@ jobs:
                 workspace:
                 - { path: ".", slug: "root" }
                 - { path: "e2e/cases", slug: "e2e" }
+                - { path: "e2e/crossbuild", slug: "e2e-crossbuild" }
         defaults:
             run:
                 working-directory: ${{ matrix.workspace.path }}

e2e/README.md

@@ -35,6 +35,16 @@ workspace above must not carry: its `.bazelrc` turns on the rules_python provide
 compatibility layer, so rules_python `py_*` targets can depend on a rules_py `py_library`.
 Its `test.sh` asserts the same dependency is rejected with the flag off.
 
+`crossbuild` hosts the rules_pycross ports (`pycross-*`): suites that force
+packages to build from their sdists — pure-Python backends, setuptools C
+extensions, pre/post-install patch phases, the distutils probe — and assert
+properties of the resulting wheels, including rebuilding them under non-host
+target platforms via `collect_wheels`. They live apart from `cases/` because
+this workspace is where the cross-compilation test matrix grows, and their
+sdist hubs carry package-specific overrides (`default_build_dependencies`,
+patches, `resource_set`) that shouldn't leak onto unrelated cases sharing a
+module — see its `MODULE.bazel` docstring.
+
 Each isolated workspace points back at repo-root rules_py with
 `local_path_override(path = "../..")`.
 

e2e/cases/MODULE.bazel

@@ -104,10 +104,6 @@ include("//oci:setup.MODULE.bazel")
 include("//pbs-cc-toolchain:setup.MODULE.bazel")
 include("//pth-namespace-547:setup.MODULE.bazel")
 include("//pyarrow-dot-dir-1420:setup.MODULE.bazel")
-include("//pycross-distutils-probe:setup.MODULE.bazel")
-include("//pycross-patches:setup.MODULE.bazel")
-include("//pycross-pure-python:setup.MODULE.bazel")
-include("//pycross-setuptools:setup.MODULE.bazel")
 include("//pytest-anyio-plugin:setup.MODULE.bazel")
 include("//pytest-main-867:setup.MODULE.bazel")
 include("//pytest-mock-530:setup.MODULE.bazel")

e2e/cases/tools/BUILD.bazel

@@ -1,13 +1,10 @@
 # Shared helpers consumed by //... via load("//tools:...").
 
-load("@aspect_rules_py//py:defs.bzl", "py_binary")
-
 # Consumed cross-package by the `assert_tar_listing` macro (//tools:asserts.bzl),
 # which declares a py_test with this script as `main` in the caller's package.
 exports_files([
     "assert_absent.py",
     "assert_ownership.py",
-    "check_wheel_tags.py",
 ])
 
 platform(
@@ -18,10 +15,3 @@ platform(
     ],
     visibility = ["//visibility:public"],
 )
-
-py_binary(
-    name = "collect_wheels_tool",
-    srcs = ["collect_wheels.py"],
-    main = "collect_wheels.py",
-    visibility = ["//visibility:public"],
-)

e2e/crossbuild/.bazelrc

@@ -0,0 +1,15 @@
+# Match Bazel 9's default. Without this, PySdistNativeBuild actions on
+# Bazel 8 run without a default PATH, and clang's compiled-in default
+# linker (`ld`, not bundled with the hermetic LLVM toolchain) can't be
+# located. With it on, Bazel injects a static PATH=/bin:/usr/bin:/usr/local/bin
+# so clang's PATH search hits the runner's /usr/bin/ld.
+common --incompatible_strict_action_env
+
+# Enable path mapping so WhlInstall actions are exercised with
+# supports-path-mapping. Actions that declare the execution requirement get
+# configuration-stripped cache keys; those that don't still work normally.
+build --experimental_output_paths=strip
+
+# Build without the bytes
+common:ci --remote_download_outputs=minimal
+common:ci --nobuild_runfile_links

e2e/crossbuild/.bazelversion

@@ -0,0 +1,7 @@
+8.6.0
+# The first line of this file is used by Bazelisk and Bazel to be sure
+# the right version of Bazel is used to build and test this repo.
+# This also defines which version is used on CI.
+#
+# Note that you should also run integration_tests against other Bazel
+# versions you support.

e2e/crossbuild/MODULE.bazel

@@ -0,0 +1,54 @@
+"""Isolated workspace for cross-platform source-build (crossbuild) suites.
+
+Hosts the rules_pycross ports: every case here forces packages to build from
+their sdists and asserts properties of the resulting wheels across target
+platforms. They live apart from `e2e/cases` because this workspace is where
+the cross-compilation test matrix grows; keeping the sdist-build hubs out of
+the shared `cases/` module also keeps their package-specific overrides
+(`default_build_dependencies`, patches, `resource_set`) from leaking onto
+unrelated cases sharing that workspace.
+"""
+
+bazel_dep(name = "aspect_rules_py")
+bazel_dep(name = "bazel_lib", version = "3.0.0")
+bazel_dep(name = "platforms", version = "1.0.0")
+bazel_dep(name = "llvm", version = "0.8.3")
+
+local_path_override(
+    module_name = "aspect_rules_py",
+    path = "../..",
+)
+
+interpreters = use_extension("@aspect_rules_py//py:extensions.bzl", "python_interpreters")
+interpreters.configure(
+    releases = [
+        "20260303",
+        "20251031",
+    ],
+)
+interpreters.toolchain(
+    python_version = "3.12",
+)
+interpreters.toolchain(
+    python_version = "3.13",
+)
+use_repo(interpreters, "python_interpreters")
+
+register_toolchains("@python_interpreters//:all")
+
+tools = use_extension("@aspect_rules_py//py:extensions.bzl", "py_tools")
+tools.rules_py_tools()
+use_repo(tools, "rules_py_tools")
+
+register_toolchains("@rules_py_tools//:all")
+
+register_toolchains("@llvm//toolchain:all")
+
+uv_bin = use_extension("@aspect_rules_py//uv:extensions.bzl", "uv_bin")
+uv_bin.toolchain(version = "0.11.21")
+use_repo(uv_bin, "uv")
+
+include("//pycross-distutils-probe:setup.MODULE.bazel")
+include("//pycross-patches:setup.MODULE.bazel")
+include("//pycross-pure-python:setup.MODULE.bazel")
+include("//pycross-setuptools:setup.MODULE.bazel")