Use `os.execvp` for `poetry run` (#1236)

* Use os.execvp for poetry run

* Use subprocess.Popen for Windows

* Handle env kwargs

poetry/console/commands/run.py

@@ -40,15 +40,13 @@ class RunCommand(EnvCommand):
         cmd = ["python", "-c"]
         cmd = ["python", "-c"]
 
 
         cmd += [
         cmd += [
-            '"import sys; '
+            "import sys; "
             "from importlib import import_module; "
             "from importlib import import_module; "
             "sys.argv = {!r}; {}"
             "sys.argv = {!r}; {}"
-            "import_module('{}').{}()\"".format(
-                args, src_in_sys_path, module, callable_
-            )
+            "import_module('{}').{}()".format(args, src_in_sys_path, module, callable_)
         ]
         ]
 
 
-        return self.env.run(*cmd, shell=True, call=True)
+        return self.env.execute(*cmd)
 
 
     @property
     @property
     def _module(self):
     def _module(self):

poetry/utils/env.py

@@ -712,7 +712,16 @@ class Env(object):
     def execute(self, bin, *args, **kwargs):
     def execute(self, bin, *args, **kwargs):
         bin = self._bin(bin)
         bin = self._bin(bin)
 
 
-        return subprocess.call([bin] + list(args), **kwargs)
+        if not self._is_windows:
+            args = [bin] + list(args)
+            if "env" in kwargs:
+                return os.execvpe(bin, args, kwargs["env"])
+            else:
+                return os.execvp(bin, args)
+        else:
+            exe = subprocess.Popen([bin] + list(args), **kwargs)
+            exe.communicate()
+            return exe.returncode
 
 
     def is_venv(self):  # type: () -> bool
     def is_venv(self):  # type: () -> bool
         raise NotImplementedError()
         raise NotImplementedError()