Get rid of remaining uses of init_subsystem.

[ci skip-rust-tests]

src/python/pants/backend/python/rules/pex_test.py

@@ -31,45 +31,41 @@
 from pants.testutil.engine.util import create_subsystem
 from pants.testutil.external_tool_test_base import ExternalToolTestBase
 from pants.testutil.option.util import create_options_bootstrapper
-from pants.testutil.subsystem.util import init_subsystem
 from pants.util.frozendict import FrozenDict
-from pants.util.strutil import create_path_env_var
 
 
 def test_merge_interpreter_constraints() -> None:
-    def assert_merged(*, input: List[List[str]], expected: List[str]) -> None:
-        assert PexInterpreterConstraints.merge_constraint_sets(input) == expected
+    def assert_merged(*, inp: List[List[str]], expected: List[str]) -> None:
+        assert PexInterpreterConstraints.merge_constraint_sets(inp) == expected
 
     # Multiple constraint sets get merged so that they are ANDed.
     # A & B => A & B
-    assert_merged(
-        input=[["CPython==2.7.*"], ["CPython==3.6.*"]], expected=["CPython==2.7.*,==3.6.*"]
-    )
+    assert_merged(inp=[["CPython==2.7.*"], ["CPython==3.6.*"]], expected=["CPython==2.7.*,==3.6.*"])
 
     # Multiple constraints within a single constraint set are kept separate so that they are ORed.
     # A | B => A | B
     assert_merged(
-        input=[["CPython==2.7.*", "CPython==3.6.*"]], expected=["CPython==2.7.*", "CPython==3.6.*"]
+        inp=[["CPython==2.7.*", "CPython==3.6.*"]], expected=["CPython==2.7.*", "CPython==3.6.*"]
     )
 
     # Input constraints already were ANDed.
     # A => A
-    assert_merged(input=[["CPython>=2.7,<3"]], expected=["CPython>=2.7,<3"])
+    assert_merged(inp=[["CPython>=2.7,<3"]], expected=["CPython>=2.7,<3"])
 
     # Both AND and OR.
     # (A | B) & C => (A & B) | (B & C)
     assert_merged(
-        input=[["CPython>=2.7,<3", "CPython>=3.5"], ["CPython==3.6.*"]],
+        inp=[["CPython>=2.7,<3", "CPython>=3.5"], ["CPython==3.6.*"]],
         expected=["CPython>=2.7,<3,==3.6.*", "CPython>=3.5,==3.6.*"],
     )
     # A & B & (C | D) => (A & B & C) | (A & B & D)
     assert_merged(
-        input=[["CPython==2.7.*"], ["CPython==3.6.*"], ["CPython==3.7.*", "CPython==3.8.*"]],
+        inp=[["CPython==2.7.*"], ["CPython==3.6.*"], ["CPython==3.7.*", "CPython==3.8.*"]],
         expected=["CPython==2.7.*,==3.6.*,==3.7.*", "CPython==2.7.*,==3.6.*,==3.8.*"],
     )
     # (A | B) & (C | D) => (A & C) | (A & D) | (B & C) | (B & D)
     assert_merged(
-        input=[["CPython>=2.7,<3", "CPython>=3.5"], ["CPython==3.6.*", "CPython==3.7.*"]],
+        inp=[["CPython>=2.7,<3", "CPython>=3.5"], ["CPython==3.6.*", "CPython==3.7.*"]],
         expected=[
             "CPython>=2.7,<3,==3.6.*",
             "CPython>=2.7,<3,==3.7.*",
@@ -80,7 +76,7 @@ def assert_merged(*, input: List[List[str]], expected: List[str]) -> None:
     # A & (B | C | D) & (E | F) & G =>
     # (A & B & E & G) | (A & B & F & G) | (A & C & E & G) | (A & C & F & G) | (A & D & E & G) | (A & D & F & G)
     assert_merged(
-        input=[
+        inp=[
             ["CPython==3.6.5"],
             ["CPython==2.7.14", "CPython==2.7.15", "CPython==2.7.16"],
             ["CPython>=3.6", "CPython==3.5.10"],
@@ -102,13 +98,13 @@ def assert_merged(*, input: List[List[str]], expected: List[str]) -> None:
     # But, we first deduplicate each constraint_set.  (A | B) & (A | B) can be rewritten as
     # X & X => X.
     assert_merged(
-        input=[["CPython==2.7.*", "CPython==3.6.*"], ["CPython==2.7.*", "CPython==3.6.*"]],
+        inp=[["CPython==2.7.*", "CPython==3.6.*"], ["CPython==2.7.*", "CPython==3.6.*"]],
         expected=["CPython==2.7.*", "CPython==3.6.*"],
     )
     # (A | B) & C & (A | B) => (A & C) | (B & C). Alternatively, this can be rewritten as
     # X & Y & X => X & Y.
     assert_merged(
-        input=[
+        inp=[
             ["CPython>=2.7,<3", "CPython>=3.5"],
             ["CPython==3.6.*"],
             ["CPython>=3.5", "CPython>=2.7,<3"],
@@ -117,21 +113,19 @@ def assert_merged(*, input: List[List[str]], expected: List[str]) -> None:
     )
 
     # No specifiers
-    assert_merged(input=[["CPython"]], expected=["CPython"])
-    assert_merged(input=[["CPython"], ["CPython==3.7.*"]], expected=["CPython==3.7.*"])
+    assert_merged(inp=[["CPython"]], expected=["CPython"])
+    assert_merged(inp=[["CPython"], ["CPython==3.7.*"]], expected=["CPython==3.7.*"])
 
     # No interpreter is shorthand for CPython, which is how Pex behaves
-    assert_merged(input=[[">=3.5"], ["CPython==3.7.*"]], expected=["CPython>=3.5,==3.7.*"])
+    assert_merged(inp=[[">=3.5"], ["CPython==3.7.*"]], expected=["CPython>=3.5,==3.7.*"])
 
     # Different Python interpreters, which are guaranteed to fail when ANDed but are safe when ORed.
     with pytest.raises(ValueError):
         PexInterpreterConstraints.merge_constraint_sets([["CPython==3.7.*"], ["PyPy==43.0"]])
-    assert_merged(
-        input=[["CPython==3.7.*", "PyPy==43.0"]], expected=["CPython==3.7.*", "PyPy==43.0"]
-    )
+    assert_merged(inp=[["CPython==3.7.*", "PyPy==43.0"]], expected=["CPython==3.7.*", "PyPy==43.0"])
 
     # Ensure we can handle empty input.
-    assert_merged(input=[], expected=[])
+    assert_merged(inp=[], expected=[])
 
 
 @dataclass(frozen=True)
@@ -285,9 +279,9 @@ def test_pex_execution(self) -> None:
         assert "main.py" in pex_files
         assert "subdir/sub.py" in pex_files
 
-        init_subsystem(PythonSetup)
-        python_setup = PythonSetup.global_instance()
-        env = {"PATH": create_path_env_var(python_setup.interpreter_search_paths)}
+        # We reasonably expect there to be a python interpreter on the test-running
+        # process's path.
+        env = {"PATH": os.getenv("PATH", "")}
 
         process = Process(
             argv=("python", "test.pex"),

src/python/pants/backend/python/rules/run_setup_py.py

@@ -314,11 +314,10 @@ async def run_setup_pys(
         exported_targets = list(FrozenOrderedSet(owners))
 
     py2 = is_python2(
-        (
+        python_setup.compatibilities_or_constraints(
             target_with_origin.target.get(PythonInterpreterCompatibility).value
             for target_with_origin in targets_with_origins
-        ),
-        python_setup,
+        )
     )
     chroots = await MultiGet(
         Get(SetupPyChroot, SetupPyChrootRequest(exported_target, py2))

src/python/pants/backend/python/rules/run_setup_py_test.py

@@ -45,7 +45,6 @@
 from pants.python.python_requirement import PythonRequirement
 from pants.source.source_root import SourceRootConfig
 from pants.testutil.option.util import create_options_bootstrapper
-from pants.testutil.subsystem.util import init_subsystem
 from pants.testutil.test_base import TestBase
 
 _namespace_decl = "__import__('pkg_resources').declare_namespace(__name__)"
@@ -66,10 +65,6 @@ def tgt(self, addr: str) -> Target:
         return self.request_single_product(WrappedTarget, Params(Address.parse(addr))).target
 
 
-def init_source_root():
-    init_subsystem(SourceRootConfig, options={"source": {"root_patterns": ["src/python"]}})
-
-
 class TestGenerateChroot(TestSetupPyBase):
     @classmethod
     def rules(cls):
@@ -112,7 +107,6 @@ def assert_error(self, addr: str, exc_cls: Type[Exception]):
         assert type(ex.wrapped_exceptions[0]) == exc_cls
 
     def test_generate_chroot(self) -> None:
-        init_source_root()
         self.create_file(
             "src/python/foo/bar/baz/BUILD",
             "python_library(provides=setup_py(name='baz', version='1.1.1'))",
@@ -176,7 +170,6 @@ def test_generate_chroot(self) -> None:
         )
 
     def test_invalid_binary(self) -> None:
-        init_source_root()
         self.create_file(
             "src/python/invalid_binary/BUILD",
             textwrap.dedent(
@@ -229,7 +222,7 @@ def assert_sources(
             SetupPySources,
             Params(
                 SetupPySourcesRequest(Targets([self.tgt(addr) for addr in addrs]), py2=False),
-                SourceRootConfig.global_instance(),
+                create_options_bootstrapper(args=["--source-root-patterns=src/python"]),
             ),
         )
         chroot_snapshot = self.request_single_product(Snapshot, Params(srcs.digest))
@@ -240,7 +233,6 @@ def assert_sources(
         assert expected_package_data == dict(srcs.package_data)
 
     def test_get_sources(self) -> None:
-        init_source_root()
         self.create_file(
             "src/python/foo/bar/baz/BUILD",
             textwrap.dedent(
@@ -411,7 +403,8 @@ def assert_ancestor_init_py(
         ancestor_init_py_files = self.request_single_product(
             AncestorInitPyFiles,
             Params(
-                Targets([self.tgt(addr) for addr in addrs]), SourceRootConfig.global_instance(),
+                Targets([self.tgt(addr) for addr in addrs]),
+                create_options_bootstrapper(args=["--source-root-patterns=src/python"]),
             ),
         )
         snapshots = [
@@ -423,7 +416,6 @@ def assert_ancestor_init_py(
         assert sorted(expected_init_pys) == sorted(init_py_files_found)
 
     def test_get_ancestor_init_py(self) -> None:
-        init_source_root()
         # NB: src/python/foo/bar/baz/qux/__init__.py is a target's source.
         self.create_file("src/python/foo/bar/baz/qux/BUILD", "python_library()")
         self.create_file("src/python/foo/bar/baz/qux/qux.py", "")

src/python/pants/backend/python/rules/util.py

@@ -4,7 +4,7 @@
 import io
 import os
 from collections import abc, defaultdict
-from typing import Dict, Iterable, List, Optional, Set, Tuple, cast
+from typing import Dict, Iterable, List, Set, Tuple, cast
 
 from pkg_resources import Requirement
 
@@ -13,7 +13,6 @@
 from pants.core.util_rules.strip_source_roots import SourceRootStrippedSources
 from pants.engine.fs import DigestContents
 from pants.engine.target import Target
-from pants.python.python_setup import PythonSetup
 from pants.source.source_root import SourceRootError
 from pants.util.strutil import ensure_text
 
@@ -216,15 +215,12 @@ def has_args(call_node: ast.Call, required_arg_ids: Tuple[str, ...]) -> bool:
     return False
 
 
-def is_python2(
-    compatibilities: Iterable[Optional[Iterable[str]]], python_setup: PythonSetup
-) -> bool:
+def is_python2(compatibilities_or_constraints: Iterable[str]) -> bool:
     """Checks if we should assume python2 code."""
 
     def iter_reqs():
-        for compatibility in compatibilities:
-            for constraint in python_setup.compatibility_or_constraints(compatibility):
-                yield parse_interpreter_constraint(constraint)
+        for constraint in compatibilities_or_constraints:
+            yield parse_interpreter_constraint(constraint)
 
     for req in iter_reqs():
         for python_27_ver in range(0, 18):  # The last python 2.7 version was 2.7.18.

src/python/pants/backend/python/rules/util_test.py

@@ -8,10 +8,6 @@
     distutils_repr,
     is_python2,
 )
-from pants.option.ranked_value import Rank, RankedValue
-from pants.python.python_setup import PythonSetup
-from pants.subsystem.subsystem import Subsystem
-from pants.testutil.subsystem.util import init_subsystem
 
 testdata = {
     "foo": "bar",
@@ -80,49 +76,29 @@ def test_does_not_declare_pkg_resources_namespace_package(python_src: str) -> No
 
 
 @pytest.mark.parametrize(
-    ["constraints", "compatibilities"],
+    "constraints",
     [
-        ([], [["CPython>=2.7,<3"]]),
-        (["CPython>=2.7,<3"], [None]),
-        (["CPython>=2.7,<3"], [["CPython>=2.7,<3"], ["CPython>=3.6"]]),
-        (["CPython>=2.7.13"], [None]),
-        (["CPython>=2.7.13,<2.7.16"], [None]),
-        (["CPython>=2.7.13,!=2.7.16"], [None]),
-        (["PyPy>=2.7,<3"], [None]),
+        ["CPython>=2.7,<3"],
+        ["CPython>=2.7,<3", "CPython>=3.6"],
+        ["CPython>=2.7.13"],
+        ["CPython>=2.7.13,<2.7.16"],
+        ["CPython>=2.7.13,!=2.7.16"],
+        ["PyPy>=2.7,<3"],
     ],
 )
-def test_is_python2(constraints, compatibilities):
-    Subsystem.reset()
-    init_subsystem(
-        PythonSetup,
-        {
-            PythonSetup.options_scope: {
-                "interpreter_constraints": RankedValue(Rank.CONFIG, constraints)
-            }
-        },
-    )
-    assert is_python2(compatibilities, PythonSetup.global_instance())
+def test_is_python2(constraints):
+    assert is_python2(constraints)
 
 
 @pytest.mark.parametrize(
-    ["constraints", "compatibilities"],
+    "constraints",
     [
-        ([], [["CPython>=3.6"]]),
-        (["CPython>=3.6"], [None]),
-        (["CPython>=3.7"], [["CPython>=3.6"]]),
-        (["CPython>=3.7"], [["CPython>=3.6"], ["CPython>=3.8"]]),
-        (["CPython!=2.7.*"], [None]),
-        (["PyPy>=3.6"], [None]),
+        ["CPython>=3.6"],
+        ["CPython>=3.7"],
+        ["CPython>=3.6", "CPython>=3.8"],
+        ["CPython!=2.7.*"],
+        ["PyPy>=3.6"],
     ],
 )
-def test_is_not_python2(constraints, compatibilities):
-    Subsystem.reset()
-    init_subsystem(
-        PythonSetup,
-        {
-            PythonSetup.options_scope: {
-                "interpreter_constraints": RankedValue(Rank.CONFIG, constraints)
-            }
-        },
-    )
-    assert not is_python2(compatibilities, PythonSetup.global_instance())
+def test_is_not_python2(constraints):
+    assert not is_python2(constraints)

src/python/pants/backend/python/target_types_test.py

@@ -8,12 +8,17 @@
 from pants.backend.python.subsystems.pytest import PyTest
 from pants.backend.python.target_types import PythonBinarySources, PythonTestsTimeout
 from pants.engine.addresses import Address
+from pants.engine.rules import SubsystemRule
 from pants.engine.target import InvalidFieldException
-from pants.testutil.subsystem.util import global_subsystem_instance
+from pants.testutil.option.util import create_options_bootstrapper
 from pants.testutil.test_base import TestBase
 
 
 class TestTimeout(TestBase):
+    @classmethod
+    def rules(cls):
+        return [*super().rules(), SubsystemRule(PyTest)]
+
     def test_timeout_validation(self) -> None:
         with pytest.raises(InvalidFieldException):
             PythonTestsTimeout(-100, address=Address.parse(":tests"))
@@ -28,18 +33,14 @@ def assert_timeout_calculated(
         expected: Optional[int],
         global_default: Optional[int] = None,
         global_max: Optional[int] = None,
-        timeouts_enabled: bool = True
+        timeouts_enabled: bool = True,
     ) -> None:
-        pytest = global_subsystem_instance(
-            PyTest,
-            options={
-                PyTest.options_scope: {
-                    "timeouts": timeouts_enabled,
-                    "timeout_default": global_default,
-                    "timeout_maximum": global_max,
-                }
-            },
-        )
+        args = ["--backend-packages=pants.backend.python", f"--pytest-timeouts={timeouts_enabled}"]
+        if global_default is not None:
+            args.append(f"--pytest-timeout-default={global_default}")
+        if global_max is not None:
+            args.append(f"--pytest-timeout-maximum={global_max}")
+        pytest = self.request_single_product(PyTest, create_options_bootstrapper(args=args))
         field = PythonTestsTimeout(field_value, address=Address.parse(":tests"))
         assert field.calculate_from_global_options(pytest) == expected
 

src/python/pants/python/python_setup.py

@@ -195,6 +195,15 @@ def compatibility_or_constraints(
             return self.interpreter_constraints
         return tuple(compatibility or self.interpreter_constraints)
 
+    def compatibilities_or_constraints(
+        self, compatibilities: Iterable[Optional[Iterable[str]]]
+    ) -> Tuple[str, ...]:
+        return tuple(
+            constraint
+            for compatibility in compatibilities
+            for constraint in self.compatibility_or_constraints(compatibility)
+        )
+
     @classmethod
     def expand_interpreter_search_paths(cls, interpreter_search_paths, pyenv_root_func=None):
         special_strings = {

src/python/pants/subsystem/subsystem.py

@@ -47,10 +47,7 @@ class Subsystem(SubsystemClientMixin, Optionable):
 
     class UninitializedSubsystemError(SubsystemError):
         def __init__(self, class_name, scope):
-            super().__init__(
-                f'Subsystem "{class_name}" not initialized for scope "{scope}". Is subsystem missing '
-                "from subsystem_dependencies() in a task? "
-            )
+            super().__init__(f'Subsystem "{class_name}" not initialized for scope "{scope}"')
 
     @classmethod
     def is_subsystem_type(cls, obj):

src/python/pants/testutil/BUILD

@@ -9,7 +9,6 @@ python_library(
     ':int-test-for-export',
     'src/python/pants/testutil/engine',
     'src/python/pants/testutil/option',
-    'src/python/pants/testutil/subsystem',
   ],
   provides=pants_setup_py(
     name='pantsbuild.pants.testutil',