Change how the test script runs pytest and adjust.

pex/commands/command.py

@@ -376,13 +376,17 @@ def add_arguments(self, parser):
         pass
 
     @contextmanager
-    def parsed_command(self, args=None):
-        # type: (Optional[Sequence[str]]) -> Iterator[_C]
+    def parsed_command(
+        self,
+        args=None,  # type: Optional[Sequence[str]]
+        rewrite_prog=True,  # type: bool
+    ):
+        # type: (...) -> Iterator[_C]
         logging.basicConfig(format="%(levelname)s: %(message)s", level=logging.INFO)
 
         # By default, let argparse derive prog from sys.argv[0].
         prog = self._prog
-        if os.path.basename(sys.argv[0]) == "__main__.py":
+        if os.path.basename(sys.argv[0]) == "__main__.py" and rewrite_prog:
             prog = "{python} -m {module}".format(
                 python=sys.executable, module=".".join(type(self).__module__.split(".")[:-1])
             )

testing/bin/run_tests.py

@@ -61,11 +61,8 @@ def main():
         print("No test control environment variables set.")
 
     return subprocess.call(
-        args=["pytest"] + passthrough_args[1:],
+        args=[sys.executable, "-m", "pytest"] + passthrough_args[1:],
         cwd=pex_project_dir(),
-        # N.B.: The pytest console script needs this to see the Pex project dir on the sys.path;
-        # cwd is not enough.
-        env=make_env(PYTHONPATH=pex_project_dir()),
     )
 
 

tests/commands/test_command.py

@@ -2,6 +2,7 @@
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
 import io
+import sys
 from argparse import Namespace
 from textwrap import dedent
 
@@ -73,7 +74,13 @@ def assert_output(
         assert isinstance(command, Command2)
     assert_output()
 
-    cm = main.parsed_command([])
+    cm = main.parsed_command(
+        args=[],
+        # N.B.: Help output normally tries to re-write prog depending on sys.argv. Since we're
+        # executing Main in-process, sys.argv is ours and not its; so disable prog re-writing so
+        # that we can rely on the "test_main" prog name.
+        rewrite_prog=False,
+    )
     with pytest.raises(SystemExit) as exc_info:
         cm.__enter__()
     assert 2 == exc_info.value.code