Revert "Update the self:update command"

This reverts commit 816c510.

poetry/console/commands/self/update.py

@@ -23,21 +23,7 @@ def handle(self):
         from poetry.__version__ import __version__
         from poetry.repositories.pypi_repository import PyPiRepository
         from poetry.semver import Version
-        from poetry.utils._compat import Path
         from poetry.utils._compat import decode
-        from poetry.utils.appdirs import expanduser
-
-        home = Path(expanduser("~"))
-        poetry_home = home / ".poetry"
-
-        current_file = Path(__file__)
-
-        try:
-            current_file.relative_to(poetry_home)
-        except ValueError:
-            raise RuntimeError(
-                "Poetry has not been installed with the recommended installer. Aborting."
-            )
 
         version = self.argument("version")
         if not version:
@@ -98,66 +84,38 @@ def handle(self):
 
     def update(self, release):
         from poetry.utils._compat import Path
-        from poetry.utils.appdirs import expanduser
-
-        home = Path(expanduser("~"))
-        poetry_home = home / ".poetry"
-        poetry_bin = poetry_home / "bin"
-        poetry_lib = poetry_home / "lib"
-        poetry_lib_backup = poetry_home / "lib.backup"
+        from poetry.utils.helpers import temporary_directory
 
         version = release.version
         self.line("Updating to <info>{}</info>".format(version))
 
-        if poetry_lib.exists():
-            # Backing up the current lib directory
-            if poetry_lib_backup.exists():
-                shutil.rmtree(str(poetry_lib_backup))
-
-            shutil.copytree(str(poetry_lib), str(poetry_lib_backup))
-            shutil.rmtree(str(poetry_lib))
-
-        try:
-            self._update(release, poetry_lib)
-        except Exception as e:
-            # Reverting changes
-            if poetry_lib_backup.exists():
-                if poetry_lib.exists():
-                    shutil.rmtree(str(poetry_lib))
-
-                shutil.copytree(str(poetry_lib_backup), str(poetry_lib))
-
-            message = (
-                "An error occured when updating Poetry. "
-                "The changes have been rolled back."
-            )
-
-            if self.output.is_debug():
-                message += " Original error: {}".format(e)
-
-            raise RuntimeError(message)
-        finally:
-            if poetry_lib_backup.exists():
-                shutil.rmtree(str(poetry_lib_backup))
-
-        self.line("")
-        self.line(
-            "<info>Poetry</> (<comment>{}</>) "
-            "is installed now. Great!".format(version)
-        )
-
-    def _update(self, release, lib):
-        from poetry.utils._compat import Path
-        from poetry.utils.helpers import temporary_directory
+        prefix = sys.prefix
+        base_prefix = getattr(sys, "base_prefix", None)
+        real_prefix = getattr(sys, "real_prefix", None)
+
+        prefix_poetry = self._bin_path(Path(prefix), "poetry")
+        if prefix_poetry.exists():
+            pip = self._bin_path(prefix_poetry.parent.parent, "pip").resolve()
+        elif (
+            base_prefix
+            and base_prefix != prefix
+            and self._bin_path(Path(base_prefix), "poetry").exists()
+        ):
+            pip = self._bin_path(Path(base_prefix), "pip")
+        elif real_prefix:
+            pip = self._bin_path(Path(real_prefix), "pip")
+        else:
+            pip = self._bin_path(Path(prefix), "pip")
+
+            if not pip.exists():
+                raise RuntimeError("Unable to determine poetry's path")
 
         with temporary_directory(prefix="poetry-update-") as temp_dir:
             temp_dir = Path(temp_dir)
             dist = temp_dir / "dist"
             self.line("  - Getting dependencies")
             self.process(
-                sys.executable,
-                "-m",
-                "pip",
+                str(pip),
                 "install",
                 "-U",
                 "poetry=={}".format(release.version),
@@ -184,7 +142,39 @@ def _update(self, release, lib):
                     shutil.copy(str(file), str(dest))
                     os.unlink(str(file))
 
-            shutil.copytree(dist, str(lib))
+            wheel_data = dist / "poetry-{}.dist-info".format(version) / "WHEEL"
+            with wheel_data.open() as f:
+                wheel_data = Parser().parsestr(f.read())
+
+            tag = wheel_data["Tag"]
+
+            # Repack everything and install
+            self.line("  - Updating <info>poetry</info>")
+
+            shutil.make_archive(
+                str(temp_dir / "poetry-{}-{}".format(version, tag)),
+                format="zip",
+                root_dir=str(dist),
+            )
+
+            os.rename(
+                str(temp_dir / "poetry-{}-{}.zip".format(version, tag)),
+                str(temp_dir / "poetry-{}-{}.whl".format(version, tag)),
+            )
+
+            self.process(
+                str(pip),
+                "install",
+                "--upgrade",
+                "--no-deps",
+                str(temp_dir / "poetry-{}-{}.whl".format(version, tag)),
+            )
+
+            self.line("")
+            self.line(
+                "<info>poetry</> (<comment>{}</>) "
+                "successfully installed!".format(version)
+            )
 
     def process(self, *args):
         return subprocess.check_output(list(args), stderr=subprocess.STDOUT)