Improve environment management (#1477)

* Refactor the environment management code

* Improve executable selection when current Python is incompatible

poetry/console/commands/debug/resolve.py

@@ -103,7 +103,7 @@ def handle(self):
 
             return 0
 
-        env = EnvManager(self.poetry.config).get(self.poetry.file.parent)
+        env = EnvManager(self.poetry).get()
         current_python_version = parse_constraint(
             ".".join(str(v) for v in env.version_info)
         )

poetry/console/commands/env/info.py

@@ -13,8 +13,7 @@ class EnvInfoCommand(Command):
     def handle(self):
         from poetry.utils.env import EnvManager
 
-        poetry = self.poetry
-        env = EnvManager(poetry.config).get(cwd=poetry.file.parent)
+        env = EnvManager(self.poetry).get()
 
         if self.option("path"):
             if not env.is_venv():

poetry/console/commands/env/list.py

@@ -13,11 +13,10 @@ class EnvListCommand(Command):
     def handle(self):
         from poetry.utils.env import EnvManager
 
-        poetry = self.poetry
-        manager = EnvManager(poetry.config)
-        current_env = manager.get(self.poetry.file.parent)
+        manager = EnvManager(self.poetry)
+        current_env = manager.get()
 
-        for venv in manager.list(self.poetry.file.parent):
+        for venv in manager.list():
             name = venv.path.name
             if self.option("full-path"):
                 name = str(venv.path)

poetry/console/commands/env/remove.py

@@ -15,8 +15,7 @@ class EnvRemoveCommand(Command):
     def handle(self):
         from poetry.utils.env import EnvManager
 
-        poetry = self.poetry
-        manager = EnvManager(poetry.config)
-        venv = manager.remove(self.argument("python"), poetry.file.parent)
+        manager = EnvManager(self.poetry)
+        venv = manager.remove(self.argument("python"))
 
         self.line("Deleted virtualenv: <comment>{}</comment>".format(venv.path))

poetry/console/commands/env/use.py

@@ -13,14 +13,13 @@ class EnvUseCommand(Command):
     def handle(self):
         from poetry.utils.env import EnvManager
 
-        poetry = self.poetry
-        manager = EnvManager(poetry.config)
+        manager = EnvManager(self.poetry)
 
         if self.argument("python") == "system":
-            manager.deactivate(poetry.file.parent, self._io)
+            manager.deactivate(self._io)
 
             return
 
-        env = manager.activate(self.argument("python"), poetry.file.parent, self._io)
+        env = manager.activate(self.argument("python"), self._io)
 
         self.line("Using virtualenv: <comment>{}</>".format(env.path))

poetry/console/commands/init.py

@@ -3,6 +3,7 @@
 
 import os
 import re
+import sys
 
 from typing import Dict
 from typing import List
@@ -15,7 +16,6 @@
 from poetry.utils._compat import Path
 from poetry.utils._compat import OrderedDict
 from poetry.utils._compat import urlparse
-from poetry.utils.helpers import temporary_directory
 
 from .command import Command
 from .env_command import EnvCommand
@@ -63,7 +63,7 @@ def __init__(self):
     def handle(self):
         from poetry.layouts import layout
         from poetry.utils._compat import Path
-        from poetry.utils.env import EnvManager
+        from poetry.utils.env import SystemEnv
         from poetry.vcs.git import GitConfig
 
         if (Path.cwd() / "pyproject.toml").exists():
@@ -126,7 +126,7 @@ def handle(self):
         question.set_validator(self._validate_license)
         license = self.ask(question)
 
-        current_env = EnvManager().get(Path.cwd())
+        current_env = SystemEnv(Path(sys.executable))
         default_python = "^{}".format(
             ".".join(str(v) for v in current_env.version_info[:2])
         )

poetry/console/config/application_config.py

@@ -28,10 +28,7 @@ def configure(self):
         self.add_event_listener(ConsoleEvents.PRE_HANDLE.value, self.set_env)
 
     def register_command_loggers(
-        self,
-        event,  # type: PreHandleEvent
-        event_name,  # type: str
-        _,
+        self, event, event_name, _  # type: PreHandleEvent  # type: str
     ):  # type: (...) -> None
         command = event.command.config.handler
         if not isinstance(command, Command):
@@ -70,25 +67,8 @@ def set_env(self, event, event_name, _):  # type: (PreHandleEvent, str, _) -> No
         io = event.io
         poetry = command.poetry
 
-        env_manager = EnvManager(poetry.config)
-
-        # Checking compatibility of the current environment with
-        # the python dependency specified in pyproject.toml
-        current_env = env_manager.get(poetry.file.parent)
-        supported_python = poetry.package.python_constraint
-        current_python = parse_constraint(
-            ".".join(str(v) for v in current_env.version_info[:3])
-        )
-
-        if not supported_python.allows(current_python):
-            raise RuntimeError(
-                "The current Python version ({}) is not supported by the project ({})\n"
-                "Please activate a compatible Python version.".format(
-                    current_python, poetry.package.python_versions
-                )
-            )
-
-        env = env_manager.create_venv(poetry.file.parent, io, poetry.package.name)
+        env_manager = EnvManager(poetry)
+        env = env_manager.create_venv(io)
 
         if env.is_venv() and io.is_verbose():
             io.write_line("Using virtualenv: <comment>{}</>".format(env.path))

poetry/packages/package.py

@@ -27,7 +27,7 @@
 
 class Package(object):
 
-    AVAILABLE_PYTHONS = {"2", "2.7", "3", "3.4", "3.5", "3.6", "3.7"}
+    AVAILABLE_PYTHONS = {"2", "2.7", "3", "3.4", "3.5", "3.6", "3.7", "3.8"}
 
     def __init__(self, name, version, pretty_version=None):
         """

poetry/puzzle/provider.py

@@ -38,6 +38,7 @@
 from poetry.utils.helpers import temporary_directory
 from poetry.utils.env import EnvManager
 from poetry.utils.env import EnvCommandError
+from poetry.utils.env import VirtualEnv
 from poetry.utils.inspector import Inspector
 from poetry.utils.setup_reader import SetupReader
 from poetry.utils.toml_file import TomlFile
@@ -326,9 +327,10 @@ def get_package_from_directory(
             os.chdir(str(directory))
 
             try:
-                cwd = directory
-                venv = EnvManager().get(cwd)
-                venv.run("python", "setup.py", "egg_info")
+                with temporary_directory() as tmp_dir:
+                    EnvManager.build_venv(tmp_dir)
+                    venv = VirtualEnv(Path(tmp_dir), Path(tmp_dir))
+                    venv.run("python", "setup.py", "egg_info")
             except EnvCommandError:
                 result = SetupReader.read_from_directory(directory)
                 if not result["name"]: