feat(pip_repository): Enable PyPi dep cycles

This patch adjusts the pip_repository interface to accept a new
parameter: `composite_libs`, being a list of PyPi package names which
form a cycle and must be installed together.

The intuition behind this design is that a dependency cycle {a <-> b}
is implemented simply as emplacing both a and b at once. Hence a
dependency graph {c -> a, c -> b} has the same effect.

If we modify the installation of a and b to remove their mutual
dependency, and generate a c which dominates a and b, we can then modify
the `requirement()` and `whl_requirement()` helper functions to
recognize the requirements a and b and provide a reference to c instead.

.bazelrc

@@ -3,8 +3,8 @@
 # This lets us glob() up all the files inside the examples to make them inputs to tests
 # (Note, we cannot use `common --deleted_packages` because the bazel version command doesn't support it)
 # To update these lines, run tools/bazel_integration_test/update_deleted_packages.sh
-build --deleted_packages=examples/build_file_generation,examples/build_file_generation/get_url,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/runfiles,examples/multi_python_versions,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_install,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_import,examples/py_proto_library,examples/relative_requirements,tests/compile_pip_requirements,tests/pip_repository_entry_points,tests/pip_deps
-query --deleted_packages=examples/build_file_generation,examples/build_file_generation/get_url,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/runfiles,examples/multi_python_versions,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_install,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_import,examples/py_proto_library,examples/relative_requirements,tests/compile_pip_requirements,tests/pip_repository_entry_points,tests/pip_deps
+build --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/runfiles,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_install,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,tests/compile_pip_requirements,tests/compile_pip_requirements_test_from_external_workspace,tests/ignore_root_user_error,tests/pip_repository_entry_points
+query --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/runfiles,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_install,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,tests/compile_pip_requirements,tests/compile_pip_requirements_test_from_external_workspace,tests/ignore_root_user_error,tests/pip_repository_entry_points
 
 test --test_output=errors
 

examples/pip_parse_vendored/BUILD.bazel

@@ -1,6 +1,8 @@
 load("@bazel_skylib//rules:diff_test.bzl", "diff_test")
 load("@bazel_skylib//rules:write_file.bzl", "write_file")
+load("@rules_python//python:defs.bzl", "py_test")
 load("@rules_python//python:pip.bzl", "compile_pip_requirements")
+load("//:requirements.bzl", "requirement")
 
 # This rule adds a convenient way to update the requirements.txt
 # lockfile based on the requirements.in.
@@ -20,8 +22,10 @@ genrule(
         # Replace the bazel 6.0.0 specific comment with something that bazel 5.4.0 would produce.
         # This enables this example to be run as a test under bazel 5.4.0.
         """sed -e 's#@//#//#'""",
-        """sed 's#"@python39_.*//:bin/python3"#interpreter#' >$@""",
-    ]),
+        """sed 's#"@python39_.*//:bin/python3"#interpreter#'""",
+        # Stick some buildifiler disables in as needed
+        """sed 's/^def /# buildifier: disable=function-docstring\\\ndef /g'""",
+    ]) + " >$@",
 )
 
 write_file(
@@ -50,3 +54,13 @@ diff_test(
     file1 = "requirements.bzl",
     file2 = ":make_platform_agnostic",
 )
+
+py_test(
+    name = "test",
+    srcs = ["test.py"],
+    deps = [
+        requirement("oletools"),
+        requirement("pcodedmp"),
+        requirement("requests"),
+    ],
+)

examples/pip_parse_vendored/WORKSPACE

@@ -21,6 +21,12 @@ load("@rules_python//python:pip.bzl", "pip_parse")
 # It also wouldn't be needed by users of this ruleset.
 pip_parse(
     name = "pip",
+    composite_libs = {
+        "vbap": [
+            "oletools",
+            "pcodedmp",
+        ],
+    },
     python_interpreter_target = interpreter,
     requirements_lock = "//:requirements.txt",
 )