Try to fix base executable detection, thonny#3277

thonny/common.py

@@ -391,21 +391,6 @@ def get_site_dir(symbolic_name, executable=None):
     return result if result else None
 
 
-def get_base_executable():
-    if sys.exec_prefix == sys.base_exec_prefix:
-        return sys.executable
-
-    if sys.platform == "win32":
-        guess = sys.base_exec_prefix + "\\" + os.path.basename(sys.executable)
-        if os.path.isfile(guess):
-            return normpath_with_actual_case(guess)
-
-    if os.path.islink(sys.executable):
-        return os.path.realpath(sys.executable)
-
-    raise RuntimeError("Don't know how to locate base executable")
-
-
 def get_augmented_system_path(extra_dirs):
     path_items = os.environ.get("PATH", "").split(os.pathsep)
 
@@ -807,12 +792,7 @@ def is_private_python(executable):
 
 
 def running_in_virtual_environment() -> bool:
-    return (
-        hasattr(sys, "base_prefix")
-        and sys.base_prefix != sys.prefix
-        or hasattr(sys, "real_prefix")
-        and getattr(sys, "real_prefix") != sys.prefix
-    )
+    return sys.base_prefix != sys.prefix
 
 
 def is_remote_path(s: str) -> bool:
@@ -904,3 +884,46 @@ def infer_package_url(dist):
         )
         for dist in dists
     ]
+
+
+def try_get_base_executable(executable: str) -> Optional[str]:
+    if os.path.islink(executable):
+        # a venv executable may link to another venv executable
+        return try_get_base_executable(os.path.realpath(executable))
+
+    may_be_venv_exe = False
+    for location in ["..", "."]:
+        cfg_path = os.path.join(os.path.dirname(executable), location, "pyvenv.cfg")
+
+        if not os.path.isfile(cfg_path):
+            continue
+
+        may_be_venv_exe = True
+
+        atts = {}
+        with open(cfg_path) as fp:
+            for line in fp:
+                if "=" not in line:
+                    continue
+                key, value = line.split("=", maxsplit=1)
+                atts[key.strip()] = value.strip()
+
+        if "home" not in atts:
+            logger.warning("No home in %s", cfg_path)
+            continue
+
+        if "executable" in atts:
+            return atts["executable"]
+
+    # pyvenv.cfg may be present also in non-virtual envs.
+    # I can check for this in certain case
+    if may_be_venv_exe and os.path.samefile(sys.executable, executable) and sys.prefix == sys.base_prefix:
+        may_be_venv_exe = False
+
+    if may_be_venv_exe:
+        # should only happen with venv-s before Python 3.11
+        # as Python 3.11 started recording executable in pyvenv.cfg
+        logger.warning("Could not find base executable of %s", executable)
+        return None
+    else:
+        return executable

thonny/plugins/cpython_backend/cp_back.py

@@ -45,13 +45,13 @@
     execute_with_frontend_sys_path,
     export_installed_distributions_info,
     get_augmented_system_path,
-    get_base_executable,
     get_exe_dirs,
     get_python_version_string,
     get_single_dir_child_data,
     path_startswith,
     running_in_virtual_environment,
     serialize_message,
+    try_get_base_executable,
     update_system_path,
 )
 
@@ -425,7 +425,7 @@ def _cmd_get_environment_info(self, cmd):
             prefix=sys.prefix,
             welcome_text=f"Python {get_python_version_string()} ({sys.executable})",
             executable=sys.executable,
-            base_executable=get_base_executable(),
+            base_executable=try_get_base_executable(sys.executable),
             exe_dirs=get_exe_dirs(),
             in_venv=running_in_virtual_environment(),
             python_version=get_python_version_string(),
@@ -1429,10 +1429,7 @@ def _is_library_file(filename):
     return (
         filename is None
         or path_startswith(filename, sys.prefix)
-        or hasattr(sys, "base_prefix")
-        and path_startswith(filename, sys.base_prefix)
-        or hasattr(sys, "real_prefix")
-        and path_startswith(filename, getattr(sys, "real_prefix"))
+        or path_startswith(filename, sys.base_prefix)
         or site.ENABLE_USER_SITE
         and path_startswith(filename, site.getusersitepackages())
     )

thonny/plugins/cpython_frontend/cp_front.py

@@ -5,7 +5,7 @@
 import tkinter as tk
 from logging import getLogger
 from tkinter import ttk
-from typing import Any, Dict, List, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 
 import thonny
 from thonny import get_runner, get_shell, get_workbench, ui_utils
@@ -18,10 +18,10 @@
     InlineCommand,
     InlineResponse,
     ToplevelCommand,
-    get_base_executable,
     is_private_python,
     normpath_with_actual_case,
     running_in_virtual_environment,
+    try_get_base_executable,
 )
 from thonny.languages import tr
 from thonny.misc_utils import running_on_mac_os, running_on_windows
@@ -93,7 +93,7 @@ def get_target_executable(self):
     def get_executable(self):
         return self._reported_executable
 
-    def get_base_executable(self):
+    def get_base_executable(self) -> Optional[str]:
         return self._reported_base_executable
 
     def _update_gui_updating(self, msg):
@@ -363,7 +363,10 @@ def get_new_machine_id(self) -> str:
 def get_default_cpython_executable_for_backend() -> str:
     if is_private_python(sys.executable) and running_in_virtual_environment():
         # Private venv. Make an exception and use base Python for default backend.
-        default_path = get_base_executable()
+        default_path = try_get_base_executable(sys.executable)
+        if default_path is None:
+            logger.warning("Could not find base executable of %s", sys.executable)
+            default_path = sys.executable
     else:
         default_path = sys.executable.replace("pythonw.exe", "python.exe")
 

thonny/running.py

@@ -66,6 +66,7 @@
     path_startswith,
     read_one_incoming_message_str,
     serialize_message,
+    try_get_base_executable,
     universal_relpath,
     update_system_path,
 )
@@ -1601,22 +1602,7 @@ def __init__(self, returncode=None):
 
 
 def is_venv_interpreter_of_current_interpreter(executable):
-    for location in ["..", "."]:
-        cfg_path = os.path.join(os.path.dirname(executable), location, "pyvenv.cfg")
-        if os.path.isfile(cfg_path):
-            with open(cfg_path) as fp:
-                content = fp.read()
-            for line in content.splitlines():
-                if line.replace(" ", "").startswith("home="):
-                    _, home = line.split("=", maxsplit=1)
-                    home = home.strip()
-                    if os.path.isdir(home) and (
-                        is_same_path(home, sys.prefix)
-                        or is_same_path(home, os.path.join(sys.prefix, "bin"))
-                        or is_same_path(home, os.path.join(sys.prefix, "Scripts"))
-                    ):
-                        return True
-    return False
+    return try_get_base_executable(executable) == sys.executable
 
 
 def get_environment_for_python_subprocess(target_executable) -> Dict[str, str]:

thonny/venv_dialog.py

@@ -41,7 +41,9 @@ def populate_main_frame(self):
 
         logger.info("Current base executable: %r", current_base_cpython)
 
-        if current_base_cpython is not None and current_base_cpython not in exes:
+        if current_base_cpython is not None:
+            if current_base_cpython in exes:
+                exes.remove(current_base_cpython)
             exes.insert(0, current_base_cpython)
 
         browse_button_width = 2 if get_workbench().is_using_aqua_based_theme() else 3