Fix Windows test skips and daemon launches.

More work towards pex-tool#2658.

pex/docs/server.py

@@ -14,7 +14,7 @@
 from pex.cache.dirs import CacheDir
 from pex.common import safe_open
 from pex.os import kill
-from pex.subprocess import subprocess_daemon_kwargs
+from pex.subprocess import launch_python_daemon
 from pex.typing import TYPE_CHECKING
 from pex.version import __version__
 
@@ -163,14 +163,13 @@ def launch(
     # ephemeral port chosen.
     env.update(PYTHONUNBUFFERED="1")
     with safe_open(log, "w") as fp:
-        process = subprocess.Popen(
+        process = launch_python_daemon(
             args=[sys.executable, "-m", http_server_module, str(port)],
             env=env,
             cwd=document_root,
             bufsize=1,
             stdout=fp.fileno(),
             stderr=subprocess.STDOUT,
-            **subprocess_daemon_kwargs()
         )
 
     pidfile = Pidfile.record(server_log=log, pid=process.pid, timeout=timeout)

pex/subprocess.py

@@ -11,7 +11,7 @@
 from pex.typing import TYPE_CHECKING
 
 if TYPE_CHECKING:
-    from typing import Any, Dict
+    from typing import Any, Dict, List
 
 
 def subprocess_daemon_kwargs():
@@ -33,3 +33,18 @@ def subprocess_daemon_kwargs():
             # The os.setsid function is not available on Windows.
             "preexec_fn": os.setsid  # type: ignore[attr-defined]
         }
+
+
+def launch_python_daemon(
+    args,  # type: List[str]
+    **kwargs  # type: Any
+):
+    # type: (...) -> subprocess.Popen
+    if WINDOWS:
+        python, _ = os.path.splitext(os.path.basename(args[0]))
+        if python == "python":
+            pythonw = os.path.join(os.path.dirname(args[0]), "pythonw.exe")
+            if os.path.exists(pythonw):
+                args[0] = pythonw
+    kwargs.update(subprocess_daemon_kwargs())
+    return subprocess.Popen(args=args, **kwargs)

testing/devpi.py

@@ -17,7 +17,7 @@
 from pex.common import safe_open, safe_rmtree
 from pex.interpreter import PythonInterpreter
 from pex.interpreter_constraints import InterpreterConstraint
-from pex.subprocess import subprocess_daemon_kwargs
+from pex.subprocess import launch_python_daemon
 from pex.typing import TYPE_CHECKING, cast
 from pex.venv.virtualenv import InvalidVirtualenvError, Virtualenv
 from testing import PEX_TEST_DEV_ROOT
@@ -197,7 +197,7 @@ def launch(
 
     log = os.path.join(DEVPI_DIR, "log.txt")
     with safe_open(log, "w") as fp:
-        process = subprocess.Popen(
+        process = launch_python_daemon(
             args=devpi_server.launch_args(
                 "--host",
                 host,
@@ -211,7 +211,6 @@ def launch(
             cwd=DEVPI_DIR,
             stdout=fp.fileno(),
             stderr=subprocess.STDOUT,
-            **subprocess_daemon_kwargs()
         )
 
     pidfile = Pidfile.record(log=log, pid=process.pid, timeout=timeout)

tests/integration/test_sh_boot.py

@@ -12,6 +12,7 @@
 
 from pex.common import safe_open
 from pex.layout import Layout
+from pex.os import WINDOWS
 from pex.typing import TYPE_CHECKING
 from testing import all_pythons, make_env, run_pex_command
 from testing.pytest.tmp import Tempdir
@@ -20,6 +21,13 @@
     from typing import Any, Iterable, Iterator, List, Text, Tuple
 
 
+if WINDOWS:
+    pytest.skip(
+        "The --sh-boot shebang launch trick only works on systems with shebang support.",
+        allow_module_level=True,
+    )
+
+
 @pytest.mark.parametrize(
     ["execution_mode_args"],
     [

tests/integration/test_shebang_length_limit.py

@@ -53,7 +53,7 @@ def find_max_length(
 # Pytest fails to cleanup tmp dirs used probing file_path_length_limit and this squashes a very
 # large ream of warnings.
 if WINDOWS:
-    pytestmark = pytest.mark.skip("The current process of probing limits can break Windows.")
+    pytest.skip("The current process of probing limits can break Windows.", allow_module_level=True)
 else:
     pytestmark = pytest.mark.filterwarnings(
         "ignore:\\(rm_rf\\) error removing.*:pytest.PytestWarning"