Fix generated scripts use host version info rather than target

docs/changelog/1600.bugfix.rst

@@ -0,0 +1 @@
+Fix generated scripts use host version info rather than target - by :user:`gaborbernat`.

src/virtualenv/seed/via_app_data/pip_install/base.py

@@ -4,9 +4,12 @@
 import os
 import re
 import shutil
+import sys
 import zipfile
 from abc import ABCMeta, abstractmethod
+from contextlib import contextmanager
 from tempfile import mkdtemp
+from threading import Lock
 
 from six import PY3, add_metaclass
 
@@ -17,6 +20,8 @@
 
 @add_metaclass(ABCMeta)
 class PipInstall(object):
+    lock = Lock()
+
     def __init__(self, wheel, creator, image_folder):
         self._wheel = wheel
         self._creator = creator
@@ -29,7 +34,7 @@ def __init__(self, wheel, creator, image_folder):
     def _sync(self, src, dst):
         raise NotImplementedError
 
-    def install(self):
+    def install(self, version_info):
         self._extracted = True
         # sync image
         for filename in self._image_dir.iterdir():
@@ -44,7 +49,7 @@ def install(self):
         consoles = set()
         script_dir = self._creator.script_dir
         for name, module in self._console_scripts.items():
-            consoles.update(self._create_console_entry_point(name, module, script_dir))
+            consoles.update(self._create_console_entry_point(name, module, script_dir, version_info))
         logging.debug("generated console scripts %s", " ".join(i.name for i in consoles))
 
     def build_image(self):
@@ -77,10 +82,11 @@ def _generate_new_files(self):
         try:
             to_folder = Path(folder)
             rel = os.path.relpath(ensure_text(str(self._creator.script_dir)), ensure_text(str(self._creator.purelib)))
+            version_info = self._creator.interpreter.version_info
             for name, module in self._console_scripts.items():
                 new_files.update(
                     Path(os.path.normpath(ensure_text(str(self._image_dir / rel / i.name))))
-                    for i in self._create_console_entry_point(name, module, to_folder)
+                    for i in self._create_console_entry_point(name, module, to_folder, version_info)
                 )
         finally:
             shutil.rmtree(folder, ignore_errors=True)
@@ -123,7 +129,7 @@ def _console_scripts(self):
                         self._console_entry_points[name] = value
         return self._console_entry_points
 
-    def _create_console_entry_point(self, name, value, to_folder):
+    def _create_console_entry_point(self, name, value, to_folder, version_info):
         result = []
         from distlib.scripts import ScriptMaker
 
@@ -133,10 +139,25 @@ def _create_console_entry_point(self, name, value, to_folder):
         maker.set_mode = True  # ensure they are executable
         maker.executable = str(self._creator.exe)
         specification = "{} = {}".format(name, value)
-        new_files = maker.make(specification)
+        with self.switch_sys_version(version_info):
+            new_files = maker.make(specification)
         result.extend(Path(i) for i in new_files)
         return result
 
+    @contextmanager
+    def switch_sys_version(self, version_info):
+        """
+        Patch until upstream distutils supports creating scripts with different python target
+        https://bitbucket.org/pypa/distlib/issues/134/allow-specifying-the-version-information
+        """
+        previous = sys.version_info
+        with self.lock:
+            sys.version_info = version_info
+            try:
+                yield
+            finally:
+                sys.version_info = previous
+
     def clear(self):
         if self._image_dir.exists():
             shutil.rmtree(ensure_text(str(self._image_dir)))

src/virtualenv/seed/via_app_data/via_app_data.py

@@ -60,7 +60,7 @@ def _install(name, wheel):
                     installer.clear()
                 if not installer.has_image():
                     installer.build_image()
-                installer.install()
+                installer.install(creator.interpreter.version_info)
 
             threads = list(Thread(target=_install, args=(n, w)) for n, w in name_to_whl.items())
             for thread in threads:

tests/unit/create/test_creator.py

@@ -290,13 +290,17 @@ def test_cross_major(cross_python, coverage_env, tmp_path, current_fastest):
         "-p",
         ensure_text(cross_python.executable),
         ensure_text(str(tmp_path)),
-        "--no-seed",
+        "--no-setuptools",
+        "--no-wheel",
         "--activators",
         "",
         "--creator",
         current_fastest,
     ]
     result = cli_run(cmd)
+    pip_scripts = {i.name.replace(".exe", "") for i in result.creator.script_dir.iterdir() if i.name.startswith("pip")}
+    major, minor = cross_python.version_info[0:2]
+    assert pip_scripts == {"pip", "pip-{}.{}".format(major, minor), "pip{}".format(major)}
     coverage_env()
     env = PythonInfo.from_exe(str(result.creator.exe))
     assert env.version_info.major != CURRENT.version_info.major