Remove version stamping

This replaces it with a simple use of importlib.metadata.version,
but that doesn't necessarily achieve the goals of version stamping,
if it is a goal for git.__version__ to be "git" when GitPython is
imported from modules from a local directory and not site-packages.

git/__init__.py

@@ -86,15 +86,16 @@
     "to_hex_sha",
 ]
 
-__version__ = "git"
+__version__: str
+
+import sys
+import warnings
 
 from typing import Any, List, Optional, Sequence, TYPE_CHECKING, Tuple, Union
 
 if TYPE_CHECKING:
     from types import ModuleType
 
-import warnings
-
 from gitdb.util import to_hex_sha
 
 from git.exc import (
@@ -193,7 +194,13 @@ def _warned_import(message: str, fullname: str) -> "ModuleType":
 
 
 def _getattr(name: str) -> Any:
-    # TODO: If __version__ is made dynamic and lazily fetched, put that case right here.
+    if name == "__version__":
+        if sys.version_info >= (3, 8):
+            from importlib.metadata import version
+        else:
+            from importlib_metadata import version
+
+        return version("GitPython")
 
     if name == "util":
         return _warned_import(

requirements.txt

@@ -1,2 +1,3 @@
 gitdb>=4.0.1,<5
+importlib-metadata;python_version<"3.8"
 typing-extensions>=3.7.4.3;python_version<"3.8"

setup.py

@@ -1,13 +1,8 @@
 #!/usr/bin/env python
 
-import os
 from pathlib import Path
-import sys
-from typing import Sequence
 
 from setuptools import setup, find_packages
-from setuptools.command.build_py import build_py as _build_py
-from setuptools.command.sdist import sdist as _sdist
 
 
 def _read_content(path: str) -> str:
@@ -21,50 +16,8 @@ def _read_content(path: str) -> str:
 long_description = _read_content("README.md")
 
 
-class build_py(_build_py):
-    def run(self) -> None:
-        init = os.path.join(self.build_lib, "git", "__init__.py")
-        if os.path.exists(init):
-            os.unlink(init)
-        _build_py.run(self)
-        _stamp_version(init)
-        self.byte_compile([init])
-
-
-class sdist(_sdist):
-    def make_release_tree(self, base_dir: str, files: Sequence) -> None:
-        _sdist.make_release_tree(self, base_dir, files)
-        orig = os.path.join("git", "__init__.py")
-        assert os.path.exists(orig), orig
-        dest = os.path.join(base_dir, orig)
-        if hasattr(os, "link") and os.path.exists(dest):
-            os.unlink(dest)
-        self.copy_file(orig, dest)
-        _stamp_version(dest)
-
-
-def _stamp_version(filename: str) -> None:
-    found, out = False, []
-    try:
-        with open(filename) as f:
-            for line in f:
-                if "__version__ =" in line:
-                    line = line.replace('"git"', "'%s'" % version)
-                    found = True
-                out.append(line)
-    except OSError:
-        print("Couldn't find file %s to stamp version" % filename, file=sys.stderr)
-
-    if found:
-        with open(filename, "w") as f:
-            f.writelines(out)
-    else:
-        print("WARNING: Couldn't find version line in file %s" % filename, file=sys.stderr)
-
-
 setup(
     name="GitPython",
-    cmdclass={"build_py": build_py, "sdist": sdist},
     version=version,
     description="GitPython is a Python library used to interact with Git repositories",
     author="Sebastian Thiel, Michael Trier",