refactor: shared-hub namespacing + ambiguous-label disambiguation

.bazelrc

@@ -6,8 +6,9 @@ common --incompatible_disallow_empty_glob=False
 # Define value used by tests
 common --define=SOME_VAR=SOME_VALUE
 
-# Set the default virtualenv to 'default'
-common --@pypi//dep_group=aspect_rules_py
+# dep_group=default is the flag's default; no explicit setting needed
+# because pyproject.toml has no [dependency-groups] table and the uv
+# extension synthesizes a single "default" group.
 
 common --incompatible_enable_cc_toolchain_resolution
 common --@llvm//config:experimental_stub_libgcc_s

BUILD.bazel

@@ -22,7 +22,7 @@ gazelle_python_manifest(
     name = "gazelle_python_manifest",
     hub = "pypi",
     venvs = [
-        "aspect_rules_py",
+        "",
     ],
 )
 

e2e/MODULE.bazel

@@ -470,6 +470,41 @@ uv.project(
 use_repo(uv, "pypi-pytorch")
 # }}}
 
+# For cases/uv-shared-hub-848
+# {{{
+# Distinct hub deliberately registering two projects with overlapping
+# group names ("shared") and project-unique groups ("a_only", "b_only").
+# Exercises the namespacing paths added in v2.0.
+uv.declare_hub(hub_name = "pypi_shared_848")
+uv.project(
+    hub_name = "pypi_shared_848",
+    lock = "//cases/uv-shared-hub-848/proj_a:uv.lock",
+    pyproject = "//cases/uv-shared-hub-848/proj_a:pyproject.toml",
+)
+uv.project(
+    hub_name = "pypi_shared_848",
+    lock = "//cases/uv-shared-hub-848/proj_b:uv.lock",
+    pyproject = "//cases/uv-shared-hub-848/proj_b:pyproject.toml",
+)
+use_repo(uv, "pypi_shared_848")
+# }}}
+
+# For cases/uv-synthesis-default-848
+# {{{
+# Single-project hub whose pyproject.toml has no [dependency-groups] table.
+# Exercises the synthesis fallback (empty-keyed group + `<name>` alias)
+# and the zero-config path where the dep_group flag's
+# build_setting_default of `""` makes everything resolve without any
+# .bazelrc entry.
+uv.declare_hub(hub_name = "pypi_synth_848")
+uv.project(
+    hub_name = "pypi_synth_848",
+    lock = "//cases/uv-synthesis-default-848:uv.lock",
+    pyproject = "//cases/uv-synthesis-default-848:pyproject.toml",
+)
+use_repo(uv, "pypi_synth_848")
+# }}}
+
 use_repo(uv, "pypi")
 
 register_toolchains("@uv//:all")

e2e/cases/firebase-admin-import/BUILD.bazel

@@ -38,7 +38,7 @@ load("@bazel_skylib//rules:build_test.bzl", "build_test")
 py_test(
     name = "test",
     srcs = ["test.py"],
-    dep_group = "firebase-admin-import",
+    dep_group = "firebase_admin_import",
     main = "test.py",
     deps = [
         "@pypi//firebase_admin",
@@ -52,7 +52,7 @@ py_test(
 py_test(
     name = "test_tool",
     srcs = ["test.py"],
-    dep_group = "firebase-admin-import",
+    dep_group = "firebase_admin_import",
     expose_venv = True,
     isolated = False,
     main = "test.py",
@@ -72,7 +72,7 @@ py_test(
 py_binary(
     name = "firebase_importer",
     srcs = ["test.py"],
-    dep_group = "firebase-admin-import",
+    dep_group = "firebase_admin_import",
     main = "test.py",
     deps = [
         "@pypi//firebase_admin",

e2e/cases/freethreaded-805/BUILD.bazel

@@ -26,7 +26,7 @@ _LINUX_X86_64 = [
 py_test(
     name = "test_bin",
     srcs = ["test.py"],
-    dep_group = "freethreaded-test",
+    dep_group = "freethreaded_test",
     main = "test.py",
     python_version = "3.13",
     tags = ["manual"],
@@ -46,7 +46,7 @@ platform_transition_test(
 py_test(
     name = "venv_test_bin",
     srcs = ["test.py"],
-    dep_group = "freethreaded-test",
+    dep_group = "freethreaded_test",
     expose_venv = True,
     isolated = False,
     main = "test.py",

e2e/cases/pth-namespace-547/BUILD.bazel

@@ -4,7 +4,7 @@ load("@aspect_rules_py//py:defs.bzl", "py_test")
 py_test(
     name = "test",
     srcs = ["__test__.py"],
-    dep_group = "pth-namespace-547",
+    dep_group = "pth_namespace_547",
     expose_venv = True,
     isolated = False,
     main = "__test__.py",
@@ -20,7 +20,7 @@ py_test(
 py_test(
     name = "test_legacy",
     srcs = ["__test__.py"],
-    dep_group = "pth-namespace-547",
+    dep_group = "pth_namespace_547",
     main = "__test__.py",
     deps = [
         "@pypi//jaraco_classes",

e2e/cases/pytest-main-867/BUILD.bazel

@@ -5,7 +5,7 @@ load("@aspect_rules_py//py:defs.bzl", "py_pytest_main", "py_test")
 py_test(
     name = "test_example",
     srcs = ["test_example.py"],
-    dep_group = "pytest-main-867",
+    dep_group = "pytest_main_867",
     pytest_main = True,
     deps = ["@pypi//pytest"],
 )
@@ -15,7 +15,7 @@ py_test(
 py_test(
     name = "test_naming_regression",
     srcs = ["test_example.py"],
-    dep_group = "pytest-main-867",
+    dep_group = "pytest_main_867",
     pytest_main = True,
     deps = ["@pypi//pytest"],
 )
@@ -29,7 +29,7 @@ py_test(
         "test_a.py",
         "test_b.py",
     ],
-    dep_group = "pytest-main-867",
+    dep_group = "pytest_main_867",
     pytest_main = True,
     deps = ["@pypi//pytest"],
 )
@@ -39,7 +39,7 @@ py_test(
 py_test(
     name = "test_collection_check",
     srcs = ["test_collection_check.py"],
-    dep_group = "pytest-main-867",
+    dep_group = "pytest_main_867",
     pytest_main = True,
     deps = ["@pypi//pytest"],
 )
@@ -58,7 +58,7 @@ py_test(
         "test_a.py",
         ":test_direct_main",
     ],
-    dep_group = "pytest-main-867",
+    dep_group = "pytest_main_867",
     main = ":__test__test_direct_main__.py",
     deps = [
         ":test_direct_main",

e2e/cases/pytest-mock-530/BUILD.bazel

@@ -4,7 +4,7 @@ load("@aspect_rules_py//py:defs.bzl", "py_test")
 py_test(
     name = "test_mock_py_test",
     srcs = ["test_mock.py"],
-    dep_group = "pytest-mock-530",
+    dep_group = "pytest_mock_530",
     pytest_main = True,
     deps = [
         "@pypi//pytest",
@@ -18,7 +18,7 @@ py_test(
         "__test__.py",
         "test_mock.py",
     ],
-    dep_group = "pytest-mock-530",
+    dep_group = "pytest_mock_530",
     expose_venv = True,
     isolated = False,
     main = "__test__.py",

e2e/cases/pytest-subdir-imports/BUILD.bazel

@@ -9,7 +9,7 @@ py_library(
 py_test(
     name = "test_subdir_import",
     srcs = ["tests/test_subdir.py"],
-    dep_group = "pytest-subdir-imports",
+    dep_group = "pytest_subdir_imports",
     pytest_main = True,
     deps = [
         ":lib",

e2e/cases/pytest-xdist-integration/BUILD.bazel

@@ -13,7 +13,7 @@ py_test(
         "-n",
         "2",
     ],
-    dep_group = "pytest-xdist-integration",
+    dep_group = "pytest_xdist_integration",
     pytest_main = True,
     deps = [
         "@pypi//pytest",

e2e/cases/uv-abi3-compat-853/BUILD.bazel

@@ -7,7 +7,7 @@ load("@aspect_rules_py//py:defs.bzl", "py_test")
 py_test(
     name = "test_import",
     srcs = ["test_abi3.py"],
-    dep_group = "abi3-compat",
+    dep_group = "abi3_compat",
     main = "test_abi3.py",
     python_version = "3.12",
     target_compatible_with = ["@platforms//os:linux"],
@@ -17,7 +17,7 @@ py_test(
 py_test(
     name = "test_import_venv_test",
     srcs = ["test_abi3.py"],
-    dep_group = "abi3-compat",
+    dep_group = "abi3_compat",
     expose_venv = True,
     isolated = False,
     main = "test_abi3.py",

e2e/cases/uv-gazelle-778/BUILD.bazel

@@ -1,14 +1,16 @@
 load("@aspect_rules_py//uv:defs.bzl", "gazelle_python_manifest")
 
-# Exercise generating a Gazelle manifest covering a ton of venvs
+# Exercise generating a Gazelle manifest covering several dep_groups.
+# `extras` is uv-deps-650/extras's explicit `[dependency-groups].extras`;
+# the bare `<name>` entries are the synthesized per-project aliases for
+# projects without explicit `[dependency-groups]` (airflow, say, crossbuild).
 gazelle_python_manifest(
     name = "gazelle_python_manifest",
     hub = "pypi",
-    # Note that we _merge_ the package mappings from several configurations.
     venvs = [
+        "extras",
         "airflow",
         "crossbuild",
-        "extras",
         "say",
     ],
 )

e2e/cases/uv-plus-version/BUILD.bazel

@@ -3,7 +3,7 @@ load("@aspect_rules_py//py:defs.bzl", "py_test")
 py_test(
     name = "test",
     srcs = ["__test__.py"],
-    dep_group = "plus-version",
+    dep_group = "plus_version",
     main = "__test__.py",
     python_version = "3.12",
     deps = [
@@ -14,7 +14,7 @@ py_test(
 py_test(
     name = "venv_test",
     srcs = ["__test__.py"],
-    dep_group = "plus-version",
+    dep_group = "plus_version",
     expose_venv = True,
     isolated = False,
     main = "__test__.py",

e2e/cases/uv-shared-hub-848/BUILD.bazel

@@ -0,0 +1,88 @@
+# Shared-hub regression tests.
+#
+# Hub `pypi_shared_848` has two projects (proj-a-848, proj-b-848), each with a
+# `shared` group containing `pytest` (pinned to the same version in both) and
+# a project-unique `<x>_only` group also containing `pytest`. This shape
+# exercises:
+#
+#   - Multi-project hub coexistence (same hub, same-named "shared" group)
+#   - Version-equality dedup: when both projects provide `pytest` in `shared`
+#     at the same version, the unqualified `@hub//pytest` resolves to one
+#     canonical project's target rather than tripping Bazel's "multiple keys
+#     match" (which would only fire on a real version conflict).
+#   - Project-qualified labels (`@hub//.<project>:pytest`) routing
+#     deterministically per project regardless of overlap.
+#   - Unqualified labels under unique-owner groups (a_only, b_only).
+
+load("@aspect_rules_py//py:defs.bzl", "py_test")
+
+# Qualified labels, dep_group=shared. The qualified target under
+# //.proj_a_848/.proj_b_848 selects only over its own project's groups, so it
+# is unambiguous regardless of cross-project overlap.
+py_test(
+    name = "test_qualified_a_shared",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "shared",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//project/proj_a_848:pytest"],
+)
+
+py_test(
+    name = "test_qualified_b_shared",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "shared",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//project/proj_b_848:pytest"],
+)
+
+# Version-equality dedup: both proj_a_848 and proj_b_848 pin pytest at the
+# same version in their `shared` group. The hub's unqualified //pytest alias
+# emits one arm per (group, versions) cluster — same-version clusters
+# collapse to a single canonical arm, so dep_group=shared resolves cleanly
+# instead of multi-matching.
+py_test(
+    name = "test_unqualified_shared_dedupes",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "shared",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//pytest"],
+)
+
+# Unqualified label, dep_group=a_only. Only proj_a_848 defines an `a_only`
+# group, so its select arm is the only match.
+py_test(
+    name = "test_unqualified_a_only",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "a_only",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//pytest"],
+)
+
+py_test(
+    name = "test_unqualified_b_only",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "b_only",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//pytest"],
+)
+
+# Per-project qualified flag form: `dep_group = "<stamp>/<group>"`
+# narrows the activation to a single project's group regardless of
+# cross-project overlap. The unqualified `@hub//pytest` resolves
+# unambiguously because only that project's qualified config_setting
+# matches.
+py_test(
+    name = "test_qualified_flag_a_shared",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "proj_a_848/shared",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//pytest"],
+)
+
+py_test(
+    name = "test_qualified_flag_b_shared",
+    srcs = ["test_pytest_import.py"],
+    dep_group = "proj_b_848/shared",
+    main = "test_pytest_import.py",
+    deps = ["@pypi_shared_848//pytest"],
+)

e2e/cases/uv-shared-hub-848/proj_a/BUILD.bazel

@@ -0,0 +1,6 @@
+# Marker package so the uv extension can resolve //cases/uv-shared-hub-848/proj_a:pyproject.toml.
+
+exports_files([
+    "pyproject.toml",
+    "uv.lock",
+])

e2e/cases/uv-shared-hub-848/proj_a/pyproject.toml

@@ -0,0 +1,16 @@
+[project]
+name = "proj-a-848"
+version = "0.0.0"
+requires-python = ">=3.11"
+dependencies = [
+    "pytest",
+]
+
+# Two groups:
+#   - "shared": same name as proj-b-848's "shared". Both projects provide
+#     pytest in this group, exercising the cross-project ambiguity path.
+#   - "a_only": unique to proj-a-848. Setting dep_group=a_only routes
+#     @hub//pytest to proj_a's pytest unambiguously.
+[dependency-groups]
+shared = ["proj-a-848"]
+a_only = ["proj-a-848"]