Reset sys.argv after running child script/module

pyinstrument/__main__.py

@@ -294,11 +294,11 @@ def dash_m_callback(option: str, opt: str, value: str, parser: optparse.OptionPa
                 # when called with '-m', search the cwd for that module
                 sys.path[0] = os.path.abspath(".")
 
-            sys.argv[:] = [options.module_name] + options.module_args
+            argv = [options.module_name] + options.module_args
             code = "run_module(modname, run_name='__main__', alter_sys=True)"
             globs = {"run_module": runpy.run_module, "modname": options.module_name}
         else:
-            sys.argv[:] = args
+            argv = args
             if options.from_path:
                 progname = shutil.which(args[0])
                 if progname is None:
@@ -322,10 +322,14 @@ def dash_m_callback(option: str, opt: str, value: str, parser: optparse.OptionPa
 
         profiler.start()
 
+        old_argv = sys.argv.copy()
         try:
+            sys.argv[:] = argv
             exec(code, globs, None)
         except (SystemExit, KeyboardInterrupt):
             pass
+        finally:
+            sys.argv[:] = old_argv
 
         session = profiler.stop()
 

pyinstrument/magic/magic.py

@@ -137,7 +137,7 @@ def pyinstrument(self, line, cell=None):
         )
         as_text = _active_profiler.output_text(timeline=args.timeline)
         # repr_html may be a bit fragile, but it's been stable for a while
-        display({"text/html": as_iframe._repr_html_(), "text/plain": as_text}, raw=True)
+        display({"text/html": as_iframe._repr_html_(), "text/plain": as_text}, raw=True)  # type: ignore
 
         assert not _active_profiler.is_running
         _active_profiler = None

test/test_cmdline.py

@@ -106,21 +106,22 @@ def test_module_execution_details(self, pyinstrument_invocation, tmp_path: Path)
 
         process_pyi = subprocess.run(
             [*pyinstrument_invocation, "-m", "test_module", "arg1", "arg2"],
-            # stderr=subprocess.PIPE,
+            stderr=subprocess.PIPE,
             check=True,
             cwd=tmp_path,
             text=True,
         )
         process_native = subprocess.run(
             [sys.executable, "-m", "test_module", "arg1", "arg2"],
-            # stderr=subprocess.PIPE,
+            stderr=subprocess.PIPE,
             check=True,
             cwd=tmp_path,
             text=True,
         )
 
         print("process_pyi.stderr", process_pyi.stderr)
         print("process_native.stderr", process_native.stderr)
+        assert process_native.stderr
         assert process_pyi.stderr == process_native.stderr
 
     def test_path_execution_details(self, pyinstrument_invocation, tmp_path: Path, monkeypatch):