add option virtualenvs.prefer-shell-python

src/poetry/config/config.py

@@ -38,6 +38,7 @@ class Config:
  "in-project": None,
  "path": os.path.join("{cache-dir}", "virtualenvs"),
  "options": {"always-copy": False, "system-site-packages": False},
+ "prefer-shell-python": False,
  },
  "experimental": {"new-installer": True},
  "installer": {"parallel": True, "max-workers": None},
@@ -138,6 +139,7 @@ def _get_normalizer(name: str) -> Callable:
  "virtualenvs.in-project",
  "virtualenvs.options.always-copy",
  "virtualenvs.options.system-site-packages",
+ "virtualenvs.options.prefer-shell-python",
  "experimental.new-installer",
  "installer.parallel",
  }:

src/poetry/console/application.py

@@ -1,4 +1,3 @@
-import contextlib
 import logging
 import re
 import subprocess
@@ -19,6 +18,7 @@
 from cleo.exceptions import CleoException
 from cleo.formatters.style import Style
 from cleo.io.inputs.argv_input import ArgvInput
+from cleo.io.outputs.output import Verbosity
 from poetry.core.utils._compat import PY37
 
 from poetry.__version__ import __version__
@@ -229,6 +229,30 @@ def _configure_io(self, io: "IO") -> None:
 
  return super()._configure_io(io)
 
+ def _detect_active_python(self, io: "IO") -> str:
+ executable = None
+
+ try:
+ io.write_line(
+ "Trying to detect current active python executable as specified in the config.",
+ verbosity=Verbosity.VERBOSE,
+ )
+ executable = decode(
+ subprocess.check_output(
+ list_to_shell_command(
+ ["python", "-c", '"import sys; print(sys.executable)"']
+ ),
+ shell=True,
+ ).strip()
+ )
+ io.write_line(f"Found: {executable}", verbosity=Verbosity.VERBOSE)
+ except CalledProcessError:
+ io.write_line(
+ "Unable to detect the current active python executable. Falling back to default.",
+ verbosity=Verbosity.VERBOSE,
+ )
+ return executable
+
  def register_command_loggers(
  self, event: "ConsoleCommandEvent", event_name: str, _: Any
  ) -> None:
@@ -287,28 +311,17 @@ def configure_env(
  io = event.io
  poetry = command.poetry
 
- executable = None
- find_compatible = None
-
- # add on option to trigger this
- with contextlib.suppress(CalledProcessError):
- executable = decode(
- subprocess.check_output(
- list_to_shell_command(
- [
- "python",
- "-c",
- '"import sys; print(sys.executable)"',
- ]
- ),
- shell=True,
- ).strip()
- )
- find_compatible = True
+ executable = (
+ self._detect_active_python(io)
+ if poetry.config.get("virtualenvs.prefer-shell-python")
+ else None
+ )
 
  env_manager = EnvManager(poetry)
  env = env_manager.create_venv(
- io, executable=executable, find_compatible=find_compatible
+ io,
+ executable=executable,
+ find_compatible=True if executable else None,
  )
 
  if env.is_venv() and io.is_verbose():

src/poetry/console/commands/config.py

@@ -78,6 +78,11 @@ def unique_config_values(self) -> Dict[str, Tuple[Any, Any, Any]]:
  lambda val: str(Path(val)),
  str(Path(CACHE_DIR) / "virtualenvs"),
  ),
+ "virtualenvs.prefer-shell-python": (
+ boolean_validator,
+ boolean_normalizer,
+ False,
+ ),
  "experimental.new-installer": (
  boolean_validator,
  boolean_normalizer,

tests/console/commands/test_config.py

@@ -56,6 +56,7 @@ def test_list_displays_default_value_if_not_set(
 virtualenvs.options.always-copy = false
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = {venv_path} # {config_cache_dir / 'virtualenvs'}
+virtualenvs.prefer-shell-python = false
 """
 
  assert expected == tester.io.fetch_output()
@@ -79,6 +80,7 @@ def test_list_displays_set_get_setting(
 virtualenvs.options.always-copy = false
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = {venv_path} # {config_cache_dir / 'virtualenvs'}
+virtualenvs.prefer-shell-python = false
 """
 
  assert config.set_config_source.call_count == 0
@@ -126,6 +128,7 @@ def test_list_displays_set_get_local_setting(
 virtualenvs.options.always-copy = false
 virtualenvs.options.system-site-packages = false
 virtualenvs.path = {venv_path} # {config_cache_dir / 'virtualenvs'}
+virtualenvs.prefer-shell-python = false
 """
 
  assert config.set_config_source.call_count == 1