bpo-41011: venv -- add more variables to pyvenv.cfg (GH-30382)

Author: akulakov

Lib/test/test_venv.py

@@ -19,7 +19,7 @@
 from test.support.os_helper import (can_symlink, EnvironmentVarGuard, rmtree)
 import unittest
 import venv
-from unittest.mock import patch
+from unittest.mock import patch, Mock
 
 try:
     import ctypes
@@ -114,13 +114,49 @@ def test_defaults(self):
         executable = sys._base_executable
         path = os.path.dirname(executable)
         self.assertIn('home = %s' % path, data)
+        self.assertIn('executable = %s' %
+                      os.path.realpath(sys.executable), data)
+        copies = '' if os.name=='nt' else ' --copies'
+        cmd = f'command = {sys.executable} -m venv{copies} --without-pip {self.env_dir}'
+        self.assertIn(cmd, data)
         fn = self.get_env_file(self.bindir, self.exe)
         if not os.path.exists(fn):  # diagnostics for Windows buildbot failures
             bd = self.get_env_file(self.bindir)
             print('Contents of %r:' % bd)
             print('    %r' % os.listdir(bd))
         self.assertTrue(os.path.exists(fn), 'File %r should exist.' % fn)
 
+    def test_config_file_command_key(self):
+        attrs = [
+            (None, None),
+            ('symlinks', '--copies'),
+            ('with_pip', '--without-pip'),
+            ('system_site_packages', '--system-site-packages'),
+            ('clear', '--clear'),
+            ('upgrade', '--upgrade'),
+            ('upgrade_deps', '--upgrade-deps'),
+            ('prompt', '--prompt'),
+        ]
+        for attr, opt in attrs:
+            rmtree(self.env_dir)
+            if not attr:
+                b = venv.EnvBuilder()
+            else:
+                b = venv.EnvBuilder(
+                    **{attr: False if attr in ('with_pip', 'symlinks') else True})
+            b.upgrade_dependencies = Mock() # avoid pip command to upgrade deps
+            b._setup_pip = Mock() # avoid pip setup
+            self.run_with_capture(b.create, self.env_dir)
+            data = self.get_text_file_contents('pyvenv.cfg')
+            if not attr:
+                for opt in ('--system-site-packages', '--clear', '--upgrade',
+                        '--upgrade-deps', '--prompt'):
+                    self.assertNotRegex(data, rf'command = .* {opt}')
+            elif os.name=='nt' and attr=='symlinks':
+                pass
+            else:
+                self.assertRegex(data, rf'command = .* {opt}')
+
     def test_prompt(self):
         env_name = os.path.split(self.env_dir)[1]
 

Lib/venv/__init__.py

@@ -51,6 +51,7 @@ def __init__(self, system_site_packages=False, clear=False,
         self.symlinks = symlinks
         self.upgrade = upgrade
         self.with_pip = with_pip
+        self.orig_prompt = prompt
         if prompt == '.':  # see bpo-38901
             prompt = os.path.basename(os.getcwd())
         self.prompt = prompt
@@ -178,6 +179,29 @@ def create_configuration(self, context):
             f.write('version = %d.%d.%d\n' % sys.version_info[:3])
             if self.prompt is not None:
                 f.write(f'prompt = {self.prompt!r}\n')
+            f.write('executable = %s\n' % os.path.realpath(sys.executable))
+            args = []
+            nt = os.name == 'nt'
+            if nt and self.symlinks:
+                args.append('--symlinks')
+            if not nt and not self.symlinks:
+                args.append('--copies')
+            if not self.with_pip:
+                args.append('--without-pip')
+            if self.system_site_packages:
+                args.append('--system-site-packages')
+            if self.clear:
+                args.append('--clear')
+            if self.upgrade:
+                args.append('--upgrade')
+            if self.upgrade_deps:
+                args.append('--upgrade-deps')
+            if self.orig_prompt is not None:
+                args.append(f'--prompt="{self.orig_prompt}"')
+
+            args.append(context.env_dir)
+            args = ' '.join(args)
+            f.write(f'command = {sys.executable} -m venv {args}\n')
 
     if os.name != 'nt':
         def symlink_or_copy(self, src, dst, relative_symlinks_ok=False):

Misc/NEWS.d/next/Library/2022-01-03-21-03-50.bpo-41011.uULmGi.rst

@@ -0,0 +1,3 @@
+Added two new variables to *pyvenv.cfg* which is generated by :mod:`venv`
+module: *executable* for the executable and *command* for the command line used
+to create the environment.