sysfce2 · pull · Nov 5, 2025 · Nov 5, 2025 · Nov 5, 2025 · Nov 5, 2025
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
@@ -18,7 +18,7 @@ defaults:
 
 env:
   PIP_DISABLE_PIP_VERSION_CHECK: 1
-  COVERAGE_IGOR_VERBOSE: 1
+  COVERAGE_IGOR_VERBOSE: 2
   FORCE_COLOR: 1    # Get colored pytest output
 
 permissions:

diff --git a/.github/workflows/python-nightly.yml b/.github/workflows/python-nightly.yml
@@ -20,7 +20,7 @@ defaults:
 
 env:
   PIP_DISABLE_PIP_VERSION_CHECK: 1
-  COVERAGE_IGOR_VERBOSE: 1
+  COVERAGE_IGOR_VERBOSE: 2
 
 permissions:
   contents: read

diff --git a/.github/workflows/testsuite.yml b/.github/workflows/testsuite.yml
@@ -17,7 +17,7 @@ defaults:
 
 env:
   PIP_DISABLE_PIP_VERSION_CHECK: 1
-  COVERAGE_IGOR_VERBOSE: 1
+  COVERAGE_IGOR_VERBOSE: 2
   FORCE_COLOR: 1    # Get colored pytest output
 
 permissions:

diff --git a/Makefile b/Makefile
@@ -24,7 +24,7 @@ _clean_platform:
 	@rm -f .DS_Store */.DS_Store */*/.DS_Store */*/*/.DS_Store */*/*/*/.DS_Store
 
 debug_clean:				## Delete various debugging artifacts.
-	@rm -rf /tmp/dis $$COVERAGE_DEBUG_FILE
+	@rm -rf /tmp/dis /tmp/foo.out $$COVERAGE_DEBUG_FILE
 
 clean: debug_clean _clean_platform	## Remove artifacts of test execution, installation, etc.
 	@echo "Cleaning..."

diff --git a/coverage/collector.py b/coverage/collector.py
@@ -14,7 +14,6 @@
 from typing import Any, Callable, TypeVar, cast
 
 from coverage import env
-from coverage.config import CoverageConfig
 from coverage.core import Core
 from coverage.data import CoverageData
 from coverage.debug import short_stack
@@ -60,9 +59,6 @@ class Collector:
     # the top, and resumed when they become the top again.
     _collectors: list[Collector] = []
 
-    # The concurrency settings we support here.
-    LIGHT_THREADS = {"greenlet", "eventlet", "gevent"}
-
     def __init__(
         self,
         core: Core,
@@ -112,8 +108,7 @@ def __init__(
         self.file_mapper = file_mapper
         self.branch = branch
         self.warn = warn
-        self.concurrency = concurrency
-        assert isinstance(self.concurrency, list), f"Expected a list: {self.concurrency!r}"
+        assert isinstance(concurrency, list), f"Expected a list: {concurrency!r}"
 
         self.pid = os.getpid()
 
@@ -125,37 +120,27 @@ def __init__(
 
         self.concur_id_func = None
 
-        # We can handle a few concurrency options here, but only one at a time.
-        concurrencies = set(self.concurrency)
-        unknown = concurrencies - CoverageConfig.CONCURRENCY_CHOICES
-        if unknown:
-            show = ", ".join(sorted(unknown))
-            raise ConfigError(f"Unknown concurrency choices: {show}")
-        light_threads = concurrencies & self.LIGHT_THREADS
-        if len(light_threads) > 1:
-            show = ", ".join(sorted(light_threads))
-            raise ConfigError(f"Conflicting concurrency settings: {show}")
         do_threading = False
 
         tried = "nothing"  # to satisfy pylint
         try:
-            if "greenlet" in concurrencies:
+            if "greenlet" in concurrency:
                 tried = "greenlet"
                 import greenlet
 
                 self.concur_id_func = greenlet.getcurrent
-            elif "eventlet" in concurrencies:
+            elif "eventlet" in concurrency:
                 tried = "eventlet"
                 import eventlet.greenthread
 
                 self.concur_id_func = eventlet.greenthread.getcurrent
-            elif "gevent" in concurrencies:
+            elif "gevent" in concurrency:
                 tried = "gevent"
                 import gevent
 
                 self.concur_id_func = gevent.getcurrent
 
-            if "thread" in concurrencies:
+            if "thread" in concurrency:
                 do_threading = True
         except ImportError as ex:
             msg = f"Couldn't trace with concurrency={tried}, the module isn't installed."
@@ -169,7 +154,7 @@ def __init__(
                 ),
             )
 
-        if do_threading or not concurrencies:
+        if do_threading or not concurrency:
             # It's important to import threading only if we need it.  If
             # it's imported early, and the program being measured uses
             # gevent, then gevent's monkey-patching won't work properly.

diff --git a/coverage/config.py b/coverage/config.py
@@ -390,6 +390,9 @@ def copy(self) -> CoverageConfig:
         "multiprocessing",
     }
 
+    # Mutually exclusive concurrency settings.
+    LIGHT_THREADS = {"greenlet", "eventlet", "gevent"}
+
     CONFIG_FILE_OPTIONS = [
         # These are *args for _set_attr_from_config_option:
         #   (attr, where, type_="")
@@ -563,6 +566,17 @@ def post_process(self) -> None:
         if "subprocess" in self.patch:
             self.parallel = True
 
+        # We can handle a few concurrency options here, but only one at a time.
+        concurrencies = set(self.concurrency)
+        unknown = concurrencies - self.CONCURRENCY_CHOICES
+        if unknown:
+            show = ", ".join(sorted(unknown))
+            raise ConfigError(f"Unknown concurrency choices: {show}")
+        light_threads = concurrencies & self.LIGHT_THREADS
+        if len(light_threads) > 1:
+            show = ", ".join(sorted(light_threads))
+            raise ConfigError(f"Conflicting concurrency settings: {show}")
+
     def debug_info(self) -> list[tuple[str, Any]]:
         """Make a list of (name, value) pairs for writing debug info."""
         return human_sorted_items((k, v) for k, v in self.__dict__.items() if not k.startswith("_"))

diff --git a/coverage/control.py b/coverage/control.py
@@ -563,7 +563,7 @@ def load(self) -> None:
     def _init_for_start(self) -> None:
         """Initialization for start()"""
         # Construct the collector.
-        concurrency: list[str] = self.config.concurrency or []
+        concurrency: list[str] = self.config.concurrency
         if "multiprocessing" in concurrency:
             if self.config.config_file is None:
                 raise ConfigError("multiprocessing requires a configuration file")

diff --git a/igor.py b/igor.py
@@ -52,52 +52,50 @@ def do_show_env():
         print(f"  {env} = {os.environ[env]!r}")
 
 
-def do_remove_extension(*args):
+def remove_extension(core):
     """Remove the compiled C extension, no matter what its name."""
 
+    if core == "ctrace":
+        return
+
     so_patterns = """
         tracer.so
         tracer.*.so
         tracer.pyd
         tracer.*.pyd
         """.split()
 
-    if "--from-install" in args:
-        # Get the install location using a subprocess to avoid
-        # locking the file we are about to delete
-        root = os.path.dirname(
-            subprocess.check_output(
-                [
-                    sys.executable,
-                    "-Xutf8",
-                    "-c",
-                    "import coverage; print(coverage.__file__)",
-                ],
-                encoding="utf-8",
-            ).strip(),
-        )
-        roots = [root]
-    else:
-        roots = [
-            "coverage",
-            "build/*/coverage",
-            ".tox/*/[Ll]ib/*/site-packages/coverage",
-            ".tox/*/[Ll]ib/site-packages/coverage",
-        ]
+    roots = [
+        "coverage",
+        "build/*/coverage",
+        ".tox/*/[Ll]ib/*/site-packages/coverage",
+        ".tox/*/[Ll]ib/site-packages/coverage",
+    ]
 
+    # On windows at least, we can't delete a loaded .pyd file. So move them
+    # out of the way into the tmp/ directory.
+    os.makedirs("tmp", exist_ok=True)
     for root, pattern in itertools.product(roots, so_patterns):
         pattern = os.path.join(root, pattern)
         if VERBOSITY > 1:
             print(f"Searching for {pattern} from {os.getcwd()}")
         for filename in glob.glob(pattern):
             if os.path.exists(filename):
+                hidden = f"tmp/{os.path.basename(filename)}"
                 if VERBOSITY > 1:
-                    print(f"Removing {os.path.abspath(filename)}")
+                    print(f"Moving {filename} to {hidden}")
                 try:
-                    os.remove(filename)
+                    if os.path.exists(hidden):
+                        os.remove(hidden)
                 except OSError as exc:
                     if VERBOSITY > 1:
-                        print(f"Couldn't remove {os.path.abspath(filename)}: {exc}")
+                        print(f"Couldn't remove {hidden}: {exc}")
+                else:
+                    try:
+                        os.rename(filename, hidden)
+                    except OSError as exc:
+                        if VERBOSITY > 1:
+                            print(f"Couldn't rename: {exc}")
 
 
 def label_for_core(core):
@@ -112,14 +110,17 @@ def label_for_core(core):
         raise ValueError(f"Bad core: {core!r}")
 
 
-def should_skip(core):
+def should_skip(core, metacov):
     """Is there a reason to skip these tests?
 
     Return empty string to run tests, or a message about why we are skipping
     the tests.
     """
     skipper = ""
 
+    if metacov and core == "sysmon" and ((3, 12) <= sys.version_info < (3, 14)):
+        skipper = "sysmon can't measure branches in Python 3.12-3.13"
+
     # $set_env.py: COVERAGE_TEST_CORES - List of cores to run: ctrace, pytrace, sysmon
     test_cores = os.getenv("COVERAGE_TEST_CORES")
     if test_cores:
@@ -140,7 +141,8 @@ def should_skip(core):
                     skipper = f"No C core for {platform.python_implementation()}"
 
     if skipper:
-        return f"Skipping tests {label_for_core(core)}: {skipper}"
+        what = "metacov" if metacov else "tests"
+        return f"Skipping {what} {label_for_core(core)}: {skipper}"
     else:
         return ""
 
@@ -157,10 +159,10 @@ def make_env_id(core):
 
 def run_tests(core, *runner_args):
     """The actual running of tests."""
+    remove_extension(core)
     if "COVERAGE_TESTING" not in os.environ:
         os.environ["COVERAGE_TESTING"] = "True"
     print_banner(label_for_core(core))
-
     return pytest.main(list(runner_args))
 
 
@@ -209,6 +211,8 @@ def run_tests_with_coverage(core, *runner_args):
                 if getattr(mod, "__file__", "??").startswith(covdir):
                     covmods[name] = mod
                     del sys.modules[name]
+        remove_extension(core)
+
         import coverage  # pylint: disable=reimported
 
         sys.modules.update(covmods)
@@ -246,15 +250,17 @@ def do_combine_html():
 
 def do_test_with_core(core, *runner_args):
     """Run tests with a particular core."""
+    metacov = os.getenv("COVERAGE_COVERAGE", "no") == "yes"
+
     # If we should skip these tests, skip them.
-    skip_msg = should_skip(core)
+    skip_msg = should_skip(core, metacov)
     if skip_msg:
         if VERBOSITY > 0:
             print(skip_msg)
         return None
 
     os.environ["COVERAGE_CORE"] = core
-    if os.getenv("COVERAGE_COVERAGE", "no") == "yes":
+    if metacov:
         return run_tests_with_coverage(core, *runner_args)
     else:
         return run_tests(core, *runner_args)

diff --git a/tests/test_cmdline.py b/tests/test_cmdline.py
@@ -1372,7 +1372,7 @@ def test_version(self) -> None:
         self.command_line("--version")
         out = self.stdout()
         assert "ersion " in out
-        if testenv.C_TRACER or testenv.SYS_MON:
+        if testenv.C_TRACER:
             assert "with C extension" in out
         else:
             assert "without C extension" in out

diff --git a/tests/test_concurrency.py b/tests/test_concurrency.py
@@ -251,10 +251,16 @@ def try_some_code(
             lines = line_count(code)
             assert line_counts(data)["try_it.py"] == lines
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_THREADS, reason="Can't measure threads with this core."
+    )
     def test_threads(self) -> None:
         code = (THREAD + SUM_RANGE_Q + PRINT_SUM_RANGE).format(QLIMIT=self.QLIMIT)
         self.try_some_code(code, "thread", threading)
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_THREADS, reason="Can't measure threads with this core."
+    )
     def test_threads_simple_code(self) -> None:
         code = SIMPLE.format(QLIMIT=self.QLIMIT)
         self.try_some_code(code, "thread", threading)
@@ -318,6 +324,9 @@ def do():
         self.try_some_code(BUG_330, "eventlet", eventlet, "0\n")
 
     # Sometimes a test fails due to inherent randomness. Try more times.
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_THREADS, reason="Can't measure threads with this core."
+    )
     @pytest.mark.flaky(max_runs=3)
     def test_threads_with_gevent(self) -> None:
         self.make_file(
@@ -554,6 +563,9 @@ def test_multiprocessing_and_gevent(self, start_method: str) -> None:
             start_method=start_method,
         )
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_BRANCHES, reason="Can't measure branches with this core"
+    )
     def test_multiprocessing_with_branching(self, start_method: str) -> None:
         nprocs = 3
         upto = 30

diff --git a/tests/test_config.py b/tests/test_config.py
@@ -83,7 +83,7 @@ def test_toml_config_file(self) -> None:
             [tool.somethingelse]
             authors = ["Joe D'Ávila <[email protected]>"]
             [tool.coverage.run]
-            concurrency = ["a", "b"]
+            concurrency = ["thread", "eventlet"]
             timid = true
             data_file = ".hello_kitty.data"
             plugins = ["plugins.a_plugin"]
@@ -99,7 +99,7 @@ def test_toml_config_file(self) -> None:
         cov = coverage.Coverage()
         assert cov.config.timid
         assert not cov.config.branch
-        assert cov.config.concurrency == ["a", "b"]
+        assert cov.config.concurrency == ["thread", "eventlet"]
         assert cov.config.data_file == ".hello_kitty.data"
         assert cov.config.plugins == ["plugins.a_plugin"]
         assert cov.config.precision == 3

diff --git a/tests/test_debug.py b/tests/test_debug.py
@@ -231,7 +231,7 @@ def test_debug_sys(self) -> None:
     def test_debug_sys_ctracer(self) -> None:
         out_text = self.f1_debug_output(["sys"])
         tracer_line = re_line(r"CTracer:", out_text).strip()
-        if testenv.C_TRACER or testenv.SYS_MON:
+        if testenv.C_TRACER:
             assert tracer_line.startswith("CTracer: available from ")
         else:
             assert tracer_line == "CTracer: unavailable"

diff --git a/tests/test_process.py b/tests/test_process.py
@@ -1516,6 +1516,9 @@ def test_subprocess_in_directories(self) -> None:
         assert line_counts(data)["main.py"] == 6
         assert line_counts(data)["subproc.py"] == 2
 
+    @pytest.mark.skipif(
+        not testenv.CAN_MEASURE_BRANCHES, reason="Can't measure branches with this core"
+    )
     def test_subprocess_gets_nonfile_config(self) -> None:
         # https://github.com/nedbat/coveragepy/issues/2021
         self.make_file(